Patent US4924194A successfully refreshed from Google Patents.
← Back to Patent Explorer
US4924194A Expired / Lapsed US ⏱️ 0.0 years remaining

RF power amplifier

Assignee: Motorola Solutions Inc
•
Filing: 1989-05-19
•
Granted: 1990-05-08
•
Expires: 2009-05-19
📄 Original PDF 🌐 Google Patents 🔄 Sync Now

Abstract

Abstract An improved RF power amplifier is disclosed whereby a PIN-type diode is utilized to provide temperature tracking for the bias supply. The PIN diode provides proper temperature tracking with the bias supply while exhibiting reduced sensitivity to self-rectification. As a result, the power amplifier's bias supply is more stable and less susceptible to inaccuracies, distortion, and oscillation that may be caused by self-rectification in the presence of high RF fields, especially at UHF and 800 MHz.

Inventors

  • 👤 George F. Opas
  • 👤 Edward C. Porrett

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-09 00:16
CPC Classifications
H; H03; H03F; H03F1/00; H03F1/30; H03F1/302; H03F3/00; H03F3/189; H03F3/19

Claims Analysis

Total Claims: 24
Claim 1
Independent Claim 226 words
A power amplifier comprising: a current source, an output transistor having a base, emitter, and collector, and a voltage reference (V ref ), said output transistor emitter coupled to said V ref , a PIN-type diode (PIN) having a first terminal and a second terminal, said current source coupled to said PIN so that the current through said PIN is maintained at a substantially fixed level, one of said PIN terminals coupled to said V ref so that, when said output transistor base and said PIN are forward biased, the sense of the voltage at the other PIN terminal (V PIN ) is the same as the sense of the voltage at said output transistor base, said voltages being measured with respect to said V ref , a bias coupling circuit, and a signal input; said output transistor base coupled to said bias coupling circuit and to said signal input; said signal input having means for coupling an input signal to said output transistor base; said V PIN coupled to said bias coupling circuit; said bias coupling circuit having means for maintaining the difference between said V PIN and the voltage at said output transistor base to substantially equal zero; said power amplifier having means for maintaining the difference between the temperature of said PIN and the temperature of said output transistor to substantially equal zero.
Claim 2
Dependent Claim 226 words
A power amplifier comprising: a current source, an output transistor having a base, emitter, and collector, and a voltage reference (V ref ), said output transistor emitter coupled to said V ref , a PIN-type diode (PIN) having a first terminal and a second terminal, said current source coupled to said PIN so that the current through said PIN is maintained at a substantially fixed level, one of said PIN terminals coupled to said V ref so that, when said output transistor base and said PIN are forward biased, the sense of the voltage at the other PIN terminal (V PIN ) is the same as the sense of the voltage at said output transistor base, said voltages being measured with respect to said V ref , a bias coupling circuit, and a signal input; said output transistor base coupled to said bias coupling circuit and to said signal input; said signal input having means for coupling an input signal to said output transistor base; said V PIN coupled to said bias coupling circuit; said bias coupling circuit having means for maintaining the difference between said V PIN and the voltage at said output transistor base to substantially equal zero; said power amplifier having means for maintaining the difference between the temperature of said PIN and the temperature of said output transistor to substantially equal zero.
Claim 3
Dependent Claim 16 words
The power amplifier of claim 1 wherein said input signal comprises a radio frequency (RF) signal.
Claim 4
Dependent Claim 37 words
The power amplifier of claim 2 wherein said bias coupling circuit includes a low-pass filter (LPF) coupled in series with said output transistor base, said LPF having means for regulating the voltage at said output transistor base.
Claim 5
Dependent Claim 23 words
The power amplifier of claim 3 wherein said bias coupling circuit includes an inductor (L) coupled in series with said output transistor base.
Claim 6
Dependent Claim 41 words
The power amplifier of claim 4 wherein said bias coupling circuit includes a buffer transistor having a base, emitter, and collector, said buffer transistore emitter coupled in series with said LPF, said buffer transistor base coupled to said V PIN .
Claim 7
Dependent Claim 56 words
The power amplifier of claim 5 wherein said bias coupling circuit includes a biasing diode (D) having a first terminal and a second terminal, one of D's terminals coupled in series with V PIN so that D is forward-biased when said PIN is forward biased, the other of D's terminals coupled to said buffer transistor base.
Claim 8
Dependent Claim 19 words
The power amplifier of claim 6 wherein said PIN is located in close physical proximity to said output transistor.
Claim 9
Dependent Claim 31 words
The power amplifier of claim 7 wherein said output transistor is mounted inside an RF power transistor package and said PIN is mounted on top of said RF power transistor package.
Claim 10
Dependent Claim 29 words
The power amplifier of claim 7 wherein said output transistor is mounted inside an RF power transistor package and said PIN is mounted inside said RF power transistor package.
Claim 11
Dependent Claim 17 words
The power amplifier of claim 9 wherein said PIN is located immediately next to said output transistor.
Claim 12
Dependent Claim 224 words
A power amplifier comprising: a current source, a signal input, an output transistor having a base, emitter, and collector, and a voltage reference (V ref ), said output transistor emitter coupled to said V ref and to said signal input; a PIN-type diode (PIN) having a first terminal and a second terminal, said current source coupled to said PIN so that the current through said PIN is maintained at a substantially fixed level, one of said PIN terminals coupled to said V ref so that, when said output transistor base and said PIN are forward biased, the sense of the voltage at the other PIN terminal (V PIN ) is the same as the sense of the voltage at said output transistor base, said voltages being measured with respect to said V ref , a bias coupling circuit; said output transistor base coupled to said bias coupling circuit; said signal input having means for coupling an input signal to said output transistor emitter; said V PIN coupled to said bias coupling circuit; said bias coupling circuit having means for maintaining the difference between said V PIN and the voltage at said output transistor base to substantially equal zero; said power amplifier having means for maintaining the difference between the temperature of said PIN and the temperature of said output transistor to substantially equal zero.
Claim 13
Dependent Claim 224 words
A power amplifier comprising: a current source, a signal input, an output transistor having a base, emitter, and collector, and a voltage reference (V ref ), said output transistor emitter coupled to said V ref and to said signal input; a PIN-type diode (PIN) having a first terminal and a second terminal, said current source coupled to said PIN so that the current through said PIN is maintained at a substantially fixed level, one of said PIN terminals coupled to said V ref so that, when said output transistor base and said PIN are forward biased, the sense of the voltage at the other PIN terminal (V PIN ) is the same as the sense of the voltage at said output transistor base, said voltages being measured with respect to said V ref , a bias coupling circuit; said output transistor base coupled to said bias coupling circuit; said signal input having means for coupling an input signal to said output transistor emitter; said V PIN coupled to said bias coupling circuit; said bias coupling circuit having means for maintaining the difference between said V PIN and the voltage at said output transistor base to substantially equal zero; said power amplifier having means for maintaining the difference between the temperature of said PIN and the temperature of said output transistor to substantially equal zero.
Claim 14
Dependent Claim 16 words
The power amplifier of claim 11 wherein said input signal comprises a radio frequency (RF) signal.
Claim 15
Dependent Claim 37 words
The power amplifier of claim 12 wherein said bias coupling circuit includes a low-pass filter (LPF) coupled in series with said output transistor base, said LPF having means for regulating the voltage at said output transistor base.
Claim 16
Dependent Claim 23 words
The power amplifier of claim 13 wherein said bias coupling circuit includes an inductor (L) coupled in series with said output transistor base.
Claim 17
Dependent Claim 41 words
The power amplifier of claim 14 wherein said bias coupling circuit includes a buffer transistor having a base, emitter, and collector, said buffer transistor emitter coupled in series with said LPF, said buffer transistor base coupled to said V PIN .
Claim 18
Dependent Claim 56 words
The power amplifier of claim 15 wherein said bias coupling circuit includes a biasing diode (D) having a first terminal and a second terminal, one of D's terminals coupled in series with V PIN so that D is forward-biased when said PIN is forward biased, the other of D's terminals coupled to said buffer transistor base.
Claim 19
Dependent Claim 19 words
The power amplifier of claim 16 wherein said PIN is located in close physical proximity to said output transistor.
Claim 20
Dependent Claim 31 words
The power amplifier of claim 17 wherein said output transistor is mounted inside an RF power transistor package and said PIN is mounted on top of said RF power transistor package.
Claim 21
Dependent Claim 29 words
The power amplifier of claim 17 wherein said output transistor is mounted inside an RF power transistor package and said PIN is mounted inside said RF power transistor package.
Claim 22
Dependent Claim 17 words
The power amplifier of claim 19 wherein said PIN is located immediately next to said output transistor.
Claim 23
Dependent Claim 49 words
A linear RF power amplifier including an output transistor and a thermally-variable device thermally adjacent to said output transistor, said thermally-variable device thermally responsive to said output transistor and having means for providing temperature compensation for said output transistor, the improvement comprising: said thermally-variable device including a PIN-type diode.
Claim 24
Dependent Claim 49 words
A linear RF power amplifier including an output transistor and a thermally-variable device thermally adjacent to said output transistor, said thermally-variable device thermally responsive to said output transistor and having means for providing temperature compensation for said output transistor, the improvement comprising: said thermally-variable device including a PIN-type diode.

References Cited (Backward Citations)

US4677392A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1993-05-07 1993-11-06 1994-05-08 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1997-05-07 1997-11-06 1998-05-08 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2001-05-07 2001-11-06 2002-05-08 $7700.00 Window Closed / Lapsed

Assigned Categories & Tags

No categories assigned to this patent yet.

Assign Category Tag