CA2166376A1 - Output control circuit for transmission power amplifying circuit - Google Patents

Output control circuit for transmission power amplifying circuit

Info

Publication number
CA2166376A1
CA2166376A1 CA002166376A CA2166376A CA2166376A1 CA 2166376 A1 CA2166376 A1 CA 2166376A1 CA 002166376 A CA002166376 A CA 002166376A CA 2166376 A CA2166376 A CA 2166376A CA 2166376 A1 CA2166376 A1 CA 2166376A1
Authority
CA
Canada
Prior art keywords
signal
circuit
output
trapezoidal wave
transmission power
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Abandoned
Application number
CA002166376A
Other languages
French (fr)
Inventor
Takeshi Kobayashi
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
NEC Corp
Original Assignee
NEC Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by NEC Corp filed Critical NEC Corp
Publication of CA2166376A1 publication Critical patent/CA2166376A1/en
Abandoned legal-status Critical Current

Links

Classifications

    • HELECTRICITY
    • H03ELECTRONIC CIRCUITRY
    • H03GCONTROL OF AMPLIFICATION
    • H03G3/00Gain control in amplifiers or frequency changers without distortion of the input signal
    • H03G3/20Automatic control
    • H03G3/30Automatic control in amplifiers having semiconductor devices
    • H03G3/3036Automatic control in amplifiers having semiconductor devices in high-frequency amplifiers or in frequency-changers
    • H03G3/3042Automatic control in amplifiers having semiconductor devices in high-frequency amplifiers or in frequency-changers in modulators, frequency-changers, transmitters or power amplifiers
    • H03G3/3047Automatic control in amplifiers having semiconductor devices in high-frequency amplifiers or in frequency-changers in modulators, frequency-changers, transmitters or power amplifiers for intermittent signals, e.g. burst signals

Abstract

A higher output of two outputs from a trapezoidal wave generating circuit 4 and a pulse generating circuit 5 is produced. The control voltage signal is formed by combining the trapezoidal wave signal and the pulse signal. Sharp rising and falling edges of the pulse voltage are selected for controlling the transmission power amplifying circuit 1 in a voltage range below a predetermined voltage level, whereas gentle rising and falling edges of the trapezoidal wave signal are used for controlling the circuit 1 in a voltage range above that voltage level.

Description

6~ o OUTPUT CONTROL CIRCUIT FOR TRANSMISSION POWER
AMPLIFYING CIRCUIT
BACKGROUND OF THE INVENTION
The present invention relates to an transmission power amplifying circuit and, more particularly, to an output control circuit for amplifying the digital signals such as a digital radio transmitter.
In a radio transmitter of a TDMA system using a modulation system in which FM or other modulation carrier signals have certain envelope in general, the intermitted transmission of the power signal having sharp rise and fall waveform edges such as a burst signal causes a spread of the transmission power spectrum due to the abrupt change of the carrier wave amplitude at the rising and falling edges. This results in undesirable influence to the adjacent channels such as inter modulation.
Attempts have been made to mollify such sharp rising and falling edges by controlling the signal waveform. For example, Japanese Patent Laid-Open No. 59-226519 proposes a circuit as illustrated in Fig. 5 of the accompanying drawings for such purpose. Referring to the circuit diagram, a rectangular burst signal is applied to a burst signal input terminal BIN in response to a burst carrier signal. Upon receiving the burst signal, a control waveform with a gentle change in time is -. 216G376 ~, produced by a waveform generating circuit 14 to control a control circuit 12.
On the other hand, the burst carrier signal from the input terminal IN is amplified by the preamplifier 11 and supplied to a power amplifying circuit 13 as an input signal having an envelope similar to that of the control waveform. The envelope of the input signal is modified to make the gentle rising and falling slope waveform around the operation range of the power amplifying circuit, thereby suppressing the spread of spectrum.
Japanese Patent Laid-Open Publication No.
5-316012 discloses another method of suppressing the spectrum spread by using a control voltage having a trapezoidal waveform to produce the envelope of the transmission output signal having the trapezoidal waveform with rising and falling edges of desired slopes.
While a number of methods including the above cited methods have been proposed to suppress the spectrum spread by using gentle rising and falling edges. However, these methods merely try to make the rising and falling edges gentle, causing the following problems. It is true that the gentle rising-and falling edges suppresses the spread of the power spectrum. More gentle rising and falling edges necessitates a considerably longer time to obtain a predetermined level of the transmission - 2166371~

power signal, degrading the output response time characteristic. It is therefore determine the slope degree of rising and falling edges on the basis of the relationship between the spread of the power spectrum and the output response time characteristic in the prior methods. As a result, it is very difficult to set a sufficient gentleness of the rising and falling edges to suppress the spectrum spread within a desired level.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide an output control circuit for a transmission power amplifying circuit capable of sufficiently suppressing the spread of the power spectrum and improving the output response time characteristic.
According to the present invention, a control voltage signal for controlling the transmission power amplifying circuit is formed by combining a trapezoidal wave signal and a pulse wave signal.
The pulse wave signal having sharp rising and falling edges is used as the control signal to control the transmission power amplifying circuit in a voltage range below a predetermined power level, whereas a trapezoidal wave signal having gentle rising and falling edges is used as the control signal to control the transmission power amplifying circuit in a range above the predetermined level, ` 2166376 thereby effectively suppressing the spread of the power spectrum at a high power output level and improving the output response time characteristic or reducing the output response time.
According to an aspect of the present invention, there is provided an output control circuit for a transmission power amplifying circuit designed to amplify the power of an input signal in response to a control signal waveform comprising: a trapezoidal wave generating circuit for generating a trapezoidal wave signal having rising and falling edges gentler than those of a burst signal; a pulse generating circuit for generating a pulse signal having a sharp rising edge in synchronization with corresponding rising edge of the burst signal and a sharp falling edge slightly delayed from corresponding falling edge of the burst signal; and an adder for producing either the trapezoidal wave signal or the pulse signal, whichever having a higher level, as the control signal.
According to another aspect of the present invention, there is provided an output control circuit for a transmission power amplifying circuit designed to amplify the power of an input burst signal in response to a control signal comprising:
a first circuit for producing a trapezoidal waveform signal waveform which rises in response to the rising of the input burst signal; a second circuit -for producing a pulse signal waveform which rises in response to the rising of the input burst signal; a third circuit for selectively outputting a higher level output of the outputs from the first and second circuits; a fourth circuit for detecting an output level of the transmission power amplifying circuit; and a fifth circuit for producing a difference between the outputs of the third and fourth circuits as the control signal.
Other objects and features will clarified from the following description with reference to attached drawings.
PREFERRED EMBODIMENTS OF THE INVENTION
Now, the present invention will be described by referring to the accompanying drawings that illustrate a preferred embodiment of the present invention. Fig. 1 is a block diagram of an embodiment to be suitably used for a transmission power amplifying circuit having an automatic output control function. Referring to Fig. 1, a modulated transmission signal is supplied to a transmission power amplifying circuit 1 through a high frequency signal input terminal IN and amplified therein. The amplified signal is then outputted from an output terminal OUT. The amplification degree of the transmission power amplifying circuit 1 is controlled by a control voltage V~c supplied to an output control terminal lA provided in the circuit ` 2166376 ~, 1. Note that the degree of amplification or the output level of the transmission power amplifying circuit 1 is automatically controlled as will be described below. More specifically, part of the output signal outputted from the output terminal OUT
is extracted and detected by a diode detector circuit 2 as a voltage corresponding to the output power level. Thus detected voltage is then supplied to one of a pair of input terminals of a comparator 3 as a detection voltage Vdet. The voltage produced by the comparator 3 is used as a control voltage VAPC
for the transmission power amplifying circuit 1.
On the other hand, a burst signal input terminal BIN for receiving a burst signal is connected to a trapezoidal wave generating circuit 4 and a pulse generating circuit 5. In response to the rising and falling edges of the burst signal, the trapezoidal wave generating circuit 4 generates a trapezoidal wave having gently inclined rising and falling edges of a required voltage level. While any circuit configuration adapted to generate the trapezoidal wave may be used for the purpose of the present invention, an integration circuit may be used to generate a wave substantially equivalent to the trapezoidal wave in this embodiment. The trapezoidal wave generating circuit 4 can generate a trapezoidal wave having desired gentle slope by controlling certain parameters.

The pulse generating circuit 5 generates a pulse signal which rises in synchronization with the corresponding rising edge of the burst signal and falls with slightly delayed time from the corresponding falling edge thereof. Thus, the pulse signal having a pulse width longer than that of the burst signal is obtainable. The pulse generating circuit 5 is capable of arbitrarily setting the signal voltage level to a level lower than that of the trapezoidal wave generated by the trapezoidal wave generating circuit 4. A low-pass filter 6 is connected to the output of the trapezoidal wave generating circuit 4 to remove high frequency components from the trapezoidal wave generated by the circuit. The outputs of the low-pass filter 6 and the pulse generating circuit 5 are supplied to an adder 7. The output of the adder 7 is then supplied to the other input terminal of the comparator 3 as the reference voltage Vref.
As seen from Fig. 2, the adder 7 comprises operational amplifiers OPl and OP2 for receiving respectively the trapezoidal wave signal and the pulse signal, resistors R1 through R5 and diodes D1 and D2. The input voltages of the trapezoidal wave signal and the pulse signal are compared by feeding back the outputs of the operational amplifiers OP1 and OP2 and produces a higher voltage of the two input voltages, as the output of the adder 7.

216637~

More specifically, assuming that a 3V
trapezoidal wave signal as shown in Fig. 3(a) and a 1.5V pulse signal as shown in Fig. 3(b) are supplied to the adder 7, the higher voltage is produced so that the pulse signal having a sharp rising edge is produced as the output signal of the adder in the initial stage of the rising edge until time t1, when the rising edge exceeds the 1.5V level the output signal of the adder is switched to the trapezoidal wave signal. From then on, the adder 7 continues to produce the trapezoidal wave signal as its output until its voltage falls below the 1.5V level at time t2, when it is switched back to the pulse signal having the sharp falling edge.
The circuit having a configuration as illustrated in Fig. 1 operates in a m~nn~r as described below. As the burst signal illustrated in Fig. 4(a) is supplied to the input terminal BIN, the trapezoidal wave generating circuit 4 generates the trapezoidal wave signal having a predetermined voltage level as shown in Fig. 4(b) as its output.
The trapezoidal wave signal is then supplied to the low-pass filter 6, where high frequency components are removed to produce the trapezoidal wave signal having gentler slopes.
On the other hand, as the burst signal shown in Fig. 4(a) is supplied to the pulse generating circuit 5, a pulse signal having a pulse width wider ~, than that of the burst signal and a voltage level lower than that of the trapezoidal wave signal is produced. Supplied with the trapezoidal wave signal and the pulse signal, the adder 7 produces a trapezoidal wave signal having a desired profile as - shown in Fig. 4(e). This trapezoidal wave signal is thereafter supplied to the comparator 3 as the reference voltage Vref. The comparator 3 produces a difference between the reference voltage Vref and the detection voltage Vdet obtained by the diode detector circuit 2. This difference is supplied to a control terminal lA of the transmission power amplifying circuit 1 as the control voltage V~c to control the output of the circuit 1.
Thus, the transmission power amplifying circuit 1 amplifies the high frequency signal to an extent of amplification that corresponds to the trapezoidal wave signal having the desired profile. Note that the control voltage has a sharp rising edge corresponding to that of the pulse signal in the initial stage of rising and then shifts to gentler rising edge corresponding to that of the trapezoidal wave signal in the latter stage of rising as typically illustrated in Fig. 4(e). Accordingly, while the transmission power spectrum is spread in the initial stage of rising, such spread of spectrum may not be caused in any significance because of its low output level. When the output level is -increased, the spectrum spread can be effectively suppressed as the control voltage is switched to the gentler rising edge of the trapezoidal wave signal.
The above description may also be applied to the case of falling edge of the control voltage. In the initial stage of falling edge of the control voltage, the gentler inclination of the trapezoidal wave signal is selected for the falling edge to effectively suppress the spread of the spectrum until the voltage level goes below a given level, and the sharp falling inclination of the pulse signal is selected thereafter. Consequently, the operation of the transmission power amplifying circuit 1 is dominated by the sharp rising and falling edges of the pulse signal in a voltage range below the predetermined voltage level, and by the gentle rising and falling edges of the trapezoidal wave signal in a voltage range higher than that the predetermined voltage level, the response time characteristic of the transmission power signal is improved and the spectrum spread is effectively suppressed.
In practice, priority may be given to either the suppression of the spread of transmission power spectrum or the improvement of output power response time characteristic, or to the both, taking their balance into account by appropriately controlling the inclination of rising and falling edges of the -trapezoidal wave signal generated by the trapezoidal wave generating circuit 4 and the pulse wave signal generated by the pulse generating circuit 5 on the basis of the operating conditions of the transmitter, and the extent of amplification and the output level of the transmission power amplifying circuit 1. While the transmission power amplifying circuit 1 of the above embodiment has an automatic output control function, it may alternatively be so arranged that the output of the adder is directly applied to the control terminal of the transmission power amplifying circuit.
As described above, the control voltage signal for controlling the transmission power amplifying circuit is formed by combining the trapezoidal wave signal and the pulse signal. The pulse signal is selected for the control voltage signal in the initial stage of rising edge and then the trapezoidal wave signal is selected in the latter stage of rising edges, whereas the trapezoidal wave signal is selected in the initial stage of falling edge and then the pulse signal is selected in the latter stage of falling edge. Any possible spread of the transmission power spectrum can be effectively suppressed by the trapezoidal wave signal while the output response time can be reduced by the pulse signal.
Particularly, by selecting the voltage level of 216~37~

the pulse signal to a value smaller than that of the trapezoidal wave signal, sharp rising and falling edges of the pulse signal can be used for the control voltage in a voltage range below a predetermined level, whereas gentle rising and falling edges of the trapezoidal wave signal can be used therefor, suppressing the wide spread of the transmission power spectrum in the case of high output and reducing the output response time. The inclination of rising and falling edges can be further mollified and hence the possible spread of the transmission power spectrum can be more effectively suppressed by connecting a low-pass filter to the output of the trapezoidal wave generating circuit in order to remove high frequency components of the trapezoidal wave signal.
Furthermore, the operation of the transmission power amplifying circuit can be stabilized by adding a detector for detecting the output of the transmission power amplifying circuit and a comparator for producing the difference between the output of the adder, which is used as a reference voltage, and that of the detector and by using the output of the comparator as the control voltage for the transmission power amplifying circuit.
Changes in construction will occur to those skilled in the art and various apparently different modifications and embodiments may be made without ~, departing from the scope of the invention. The matter set forth in the foregoing description and accompanying drawings is offered by way of illustration only. It is therefore intended that the foregoing description be regarded as illustrative rather than limiting.

Claims (13)

1. An output control circuit for a transmission power amplifying circuit designed to amplify the power of an input signal in response to a control signal waveform comprising:
a trapezoidal wave generating circuit for generating a trapezoidal wave signal having rising and falling edges gentler than those of a burst signal;
a pulse generating circuit for generating a pulse signal having a sharp rising edge in synchronization with corresponding rising edge of the burst signal and a sharp falling edge slightly delayed from corresponding falling edge of the burst signal; and an adder for producing either the trapezoidal wave signal or the pulse signal, whichever having a higher level, as the control signal.
2. The output control circuit as set forth in claim 1, wherein the pulse generating circuit generates a pulse signal having a voltage level lower than that of a corresponding trapezoidal wave signal generated by the trapezoidal wave generating circuit.
3. The output control circuit as set forth in claim 1, wherein a low-pass filter for removing high frequency components from the trapezoidal wave signal is connected to the output of the trapezoidal wave generating circuit.
4. The output control circuit as set forth in claim 2, wherein a low-pass filter for removing high frequency components from the trapezoidal wave signal is connected to the output of the trapezoidal wave generating circuit.
5. The output control circuit as set forth in claims 1, further comprising a detector for detecting an output of the transmission power amplifying circuit and a comparator for obtaining a difference between the output of the adder to be used as a reference voltage and the output of the detector and outputting the difference as the control signal.
6. The output control circuit as set forth in claims 2, further comprising a detector for detecting an output of the transmission power amplifying circuit and a comparator for obtaining a difference between the output of the adder to be used as a reference voltage and the output of the detector and outputting the difference as the control signal.
7. The output control circuit as set forth in claims 3, further comprising a detector for detecting an output of the transmission power amplifying circuit and a comparator for obtaining a difference between the output of the adder to be used as a reference voltage and the output of the detector and outputting the difference as the control signal.
8. An output control circuit for a transmission power amplifying circuit designed to amplify the power of an input signal in response to a control signal waveform, the control signal waveform comprising a first waveform having a sharp rising edge, a second waveform having a gentle rising portion, a constant level portion and a gentle falling portion connected in this order, and a third waveform having a sharp falling edge, the first, second and third waveforms being connected in this order.
9. The output control circuit as set forth in claim 8, wherein the first and third waveforms are pulse waveforms and the second waveform is a trapezoidal waveform.
10. The output control circuit as set forth in claim 8, wherein the connected portions between the rising portion and the constant level portion, and between the falling portion and the constant level portion are connected in smoothened manner.
11. An output control circuit for a transmission power amplifying circuit designed to amplify the power of an input burst signal in response to a control signal comprising:
a first circuit for producing a trapezoidal waveform signal waveform which rises in response to the rising of the input burst signal;
a second circuit for producing a pulse signal waveform which rises in response to the rising of the input burst signal;
a third circuit for selectively outputting a higher level output of the outputs from the first and second circuits;
a fourth circuit for detecting an output level of the transmission power amplifying circuit; and a fifth circuit for producing a difference between the outputs of the third and fourth circuits as the control signal.
12. The output control circuit as set forth in claim 11, further comprising a low pass filter inserted between the first and third circuits.
13. The output control circuit as set forth in claim 11, wherein the second circuit is an integration circuit.
CA002166376A 1994-12-30 1995-12-29 Output control circuit for transmission power amplifying circuit Abandoned CA2166376A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP6340430A JP2571033B2 (en) 1994-12-30 1994-12-30 Output control circuit of transmission power amplifier
JP340430/1994 1994-12-30

Publications (1)

Publication Number Publication Date
CA2166376A1 true CA2166376A1 (en) 1996-07-01

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ID=18336889

Family Applications (1)

Application Number Title Priority Date Filing Date
CA002166376A Abandoned CA2166376A1 (en) 1994-12-30 1995-12-29 Output control circuit for transmission power amplifying circuit

Country Status (6)

Country Link
US (1) US5784689A (en)
EP (1) EP0720286B1 (en)
JP (1) JP2571033B2 (en)
AU (1) AU700803B2 (en)
CA (1) CA2166376A1 (en)
DE (1) DE69527931T2 (en)

Families Citing this family (41)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH10173547A (en) 1996-12-11 1998-06-26 Matsushita Electric Ind Co Ltd Transmission output detection circuit
JP3259667B2 (en) * 1997-09-02 2002-02-25 日本電気株式会社 High-speed AGC circuit
US7515896B1 (en) 1998-10-21 2009-04-07 Parkervision, Inc. Method and system for down-converting an electromagnetic signal, and transforms for same, and aperture relationships
US6061551A (en) 1998-10-21 2000-05-09 Parkervision, Inc. Method and system for down-converting electromagnetic signals
US7039372B1 (en) 1998-10-21 2006-05-02 Parkervision, Inc. Method and system for frequency up-conversion with modulation embodiments
US6370371B1 (en) 1998-10-21 2002-04-09 Parkervision, Inc. Applications of universal frequency translation
US7236754B2 (en) 1999-08-23 2007-06-26 Parkervision, Inc. Method and system for frequency up-conversion
US7209725B1 (en) 1999-01-22 2007-04-24 Parkervision, Inc Analog zero if FM decoder and embodiments thereof, such as the family radio service
US6853690B1 (en) 1999-04-16 2005-02-08 Parkervision, Inc. Method, system and apparatus for balanced frequency up-conversion of a baseband signal and 4-phase receiver and transceiver embodiments
US6879817B1 (en) 1999-04-16 2005-04-12 Parkervision, Inc. DC offset, re-radiation, and I/Q solutions using universal frequency translation technology
US7065162B1 (en) 1999-04-16 2006-06-20 Parkervision, Inc. Method and system for down-converting an electromagnetic signal, and transforms for same
US7110444B1 (en) 1999-08-04 2006-09-19 Parkervision, Inc. Wireless local area network (WLAN) using universal frequency translation technology including multi-phase embodiments and circuit implementations
US7693230B2 (en) 1999-04-16 2010-04-06 Parkervision, Inc. Apparatus and method of differential IQ frequency up-conversion
US8295406B1 (en) 1999-08-04 2012-10-23 Parkervision, Inc. Universal platform module for a plurality of communication protocols
US7010286B2 (en) 2000-04-14 2006-03-07 Parkervision, Inc. Apparatus, system, and method for down-converting and up-converting electromagnetic signals
GB2363922A (en) * 2000-06-20 2002-01-09 Ubinetics Ltd Varying duration of a bi-level signal pulse in order to control the shape of the pulse envelope of an amplifier output signal
US7454453B2 (en) 2000-11-14 2008-11-18 Parkervision, Inc. Methods, systems, and computer program products for parallel correlation and applications thereof
DE10057439A1 (en) * 2000-11-20 2002-05-23 Nokia Mobile Phones Ltd Voltage regulator has control element, comparator element and demand value circuit that derives demand signal from input voltage so it is essentially constant during load pulse
US6983025B2 (en) * 2001-04-11 2006-01-03 Tropian, Inc. High quality power ramping in a communications transmitter
US6404284B1 (en) 2001-04-19 2002-06-11 Anadigics, Inc. Amplifier bias adjustment circuit to maintain high-output third-order intermodulation distortion performance
WO2002091565A2 (en) * 2001-05-04 2002-11-14 Ok-Sang Jin Signal amplifying method, signal amplifier and devices related therewith
US7072427B2 (en) * 2001-11-09 2006-07-04 Parkervision, Inc. Method and apparatus for reducing DC offsets in a communication system
US7085335B2 (en) * 2001-11-09 2006-08-01 Parkervision, Inc. Method and apparatus for reducing DC offsets in a communication system
US6975848B2 (en) * 2002-06-04 2005-12-13 Parkervision, Inc. Method and apparatus for DC offset removal in a radio frequency communication channel
US7321640B2 (en) * 2002-06-07 2008-01-22 Parkervision, Inc. Active polyphase inverter filter for quadrature signal generation
US7460584B2 (en) 2002-07-18 2008-12-02 Parkervision, Inc. Networking methods and systems
US7379883B2 (en) 2002-07-18 2008-05-27 Parkervision, Inc. Networking methods and systems
US7327803B2 (en) 2004-10-22 2008-02-05 Parkervision, Inc. Systems and methods for vector power amplification
US7355470B2 (en) 2006-04-24 2008-04-08 Parkervision, Inc. Systems and methods of RF power transmission, modulation, and amplification, including embodiments for amplifier class transitioning
US9106316B2 (en) 2005-10-24 2015-08-11 Parkervision, Inc. Systems and methods of RF power transmission, modulation, and amplification
US8334722B2 (en) 2007-06-28 2012-12-18 Parkervision, Inc. Systems and methods of RF power transmission, modulation and amplification
US7911272B2 (en) 2007-06-19 2011-03-22 Parkervision, Inc. Systems and methods of RF power transmission, modulation, and amplification, including blended control embodiments
US8031804B2 (en) 2006-04-24 2011-10-04 Parkervision, Inc. Systems and methods of RF tower transmission, modulation, and amplification, including embodiments for compensating for waveform distortion
US7937106B2 (en) 2006-04-24 2011-05-03 ParkerVision, Inc, Systems and methods of RF power transmission, modulation, and amplification, including architectural embodiments of same
WO2008144017A1 (en) 2007-05-18 2008-11-27 Parkervision, Inc. Systems and methods of rf power transmission, modulation, and amplification
WO2008156800A1 (en) 2007-06-19 2008-12-24 Parkervision, Inc. Combiner-less multiple input single output (miso) amplification with blended control
US7768353B2 (en) * 2008-06-13 2010-08-03 Samsung Electro-Mechanics Company, Ltd. Systems and methods for switching mode power amplifier control
JP2011166590A (en) * 2010-02-12 2011-08-25 Panasonic Corp Modulation power supply circuit
EP2695294A1 (en) 2011-04-08 2014-02-12 Parkervision, Inc. Systems and methods of rf power transmission, modulation, and amplification
WO2012167111A2 (en) 2011-06-02 2012-12-06 Parkervision, Inc. Antenna control
KR20160058855A (en) 2013-09-17 2016-05-25 파커비전, 인크. Method, apparatus and system for rendering an information bearing function of time

Family Cites Families (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS59226519A (en) 1983-06-07 1984-12-19 Nec Corp Burst controlling system
FI87028C (en) * 1989-12-22 1992-11-10 Nokia Mobile Phones Ltd METHOD OF RESULT OF EFFECTIVE PROCEDURE WITHOUT SPREADING OF EFFECTIVE EFFECTS AND COVERING OF METHODS
JPH07118617B2 (en) * 1990-07-19 1995-12-18 沖電気工業株式会社 Power amplifier and transmitter
DE59105864D1 (en) * 1990-12-03 1995-08-03 Siemens Ag Modulation device for an RF power amplifier.
JP2800500B2 (en) * 1991-10-01 1998-09-21 松下電器産業株式会社 Burst transmission output control circuit
US5150075A (en) * 1991-06-03 1992-09-22 Motorola, Inc. Power amplifier ramp up method and apparatus
JP2710503B2 (en) * 1991-10-14 1998-02-10 日本電気株式会社 Output power control circuit
US5319290A (en) * 1992-01-10 1994-06-07 Rohm Co., Ltd. Motor control circuit and motor drive system using the same
JPH05316012A (en) 1992-05-07 1993-11-26 Nec Corp Output power control circuit
DE4316526B4 (en) * 1993-05-18 2005-11-10 Philips Intellectual Property & Standards Gmbh Transmitter with a controllable power amplifier

Also Published As

Publication number Publication date
AU700803B2 (en) 1999-01-14
AU4073395A (en) 1996-07-11
EP0720286A3 (en) 1997-10-22
JPH08186506A (en) 1996-07-16
US5784689A (en) 1998-07-21
EP0720286A2 (en) 1996-07-03
EP0720286B1 (en) 2002-08-28
DE69527931T2 (en) 2003-01-09
JP2571033B2 (en) 1997-01-16
DE69527931D1 (en) 2002-10-02

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FZDE Discontinued