US 7,733,173 B2Granted

Unilateral feedback power amplifier and method for realizing the same

AssigneeNational Taiwan University

InventorsZuo-Min Tsai, George D. Vendelin, Huei Wang

Life of this patent

Estimating the term…

Loading patent…

Abstract

A unilateral feedback power amplifier utilizes new feedback techniques and devices to make the amplified high-frequency signal unilateral, let the output power, power gain and impedance matching simultaneously accomplish the optimal values, and enhance the stability of the system. In this feedback amplifier, a generalized multi-port feedback circuit is in shunt with the input terminal and the output terminal of the power transistor. This generalized multi-port feedback circuit receives an amplified high-frequency signal and eliminates the reverse admittance of the amplified high-frequency signal to let the admittance value of the output amplified high-frequency signal approach zero so as to be unilateral. Moreover, the generalized multi-port feedback power amplifier differs from the conventional power amplifier of cascaded architecture in that the ground terminal of the power transistor is directly connected to the system ground. Therefore, the heat-radiating problem of the power transistor can be greatly improved.

A method for realizing unilateralization of amplified high-frequency signal comprising the step of:

establishing a multi-port feedback circuit defining a two-port input circuit and a two-port output circuit having a capacitive shunt component connected to an input line of said two-port input circuit and an output line of said two-port output circuit to make an output high-frequency signal amplified by a power transistor unilateral, said unilateral amplified high-frequency signal having an admittance value that is close to zero, said multi-port feedback circuit being a 4-port feedback circuit;
wherein said unilateral feedback power amplifier utilizes a matrix;
Y
L
=
(
-
Y
24
f
⁢
Y
33
f
⁢
Y
41
f
⁢
Y
21
d
+
Y
23
f
⁢
Y
34
f
⁢
Y
41
f
⁢
Y
21
d
+
Y
24
f
⁢
Y
31
f
⁢
Y
43
f
⁢
Y
21
d
-
Y
21
f
⁢
Y
34
f
⁢
Y
43
f
⁢
Y
21
d
-
Y
23
f
⁢
Y
31
f
⁢
Y
44
f
⁢
Y
21
d
+
Y
21
f
⁢
Y
33
f
⁢
Y
44
f
⁢
Y
21
d
+
Y
34
f
⁢
Y
41
f
⁢
Y
12
d
⁢
Y
21
d
-
Y
31
f
⁢
Y
44
f
⁢
Y
12
d
⁢
Y
21
d
+
Y
24
f
⁢
Y
32
f
⁢
Y
41
f
⁢
Y
22
d
-
Y
22
f
⁢
Y
34
f
⁢
Y
41
f
⁢
Y
22
d
-
Y
24
f
⁢
Y
33
f
⁢
Y
42
f
⁢
Y
22
d
+
Y
21
f
⁢
Y
34
f
⁢
Y
42
f
⁢
Y
22
d
+
Y
22
f
⁢
Y
31
f
⁢
Y
44
f
⁢
Y
22
d
-
Y
21
f
⁢
Y
32
f
⁢
Y
44
f
⁢
Y
22
d
-
Y
34
f
⁢
Y
41
f
⁢
Y
11
d
⁢
Y
22
d
-
Y
34
f
⁢
Y
41
f
⁢
Y
11
f
⁢
Y
22
d
+
Y
31
f
⁢
Y
44
f
⁢
Y
11
f
⁢
Y
22
d
+
Y
24
f
⁢
Y
32
f
⁢
Y
41
f
⁢
Y
opt
-
Y
24
f
⁢
Y
32
f
⁢
Y
42
f
⁢
Y
opt
-
Y
21
f
⁢
Y
34
f
⁢
Y
42
f
⁢
Y
opt
+
Y
22
f
⁢
Y
31
f
⁢
Y
44
f
⁢
Y
opt
-
Y
34
f
⁢
Y
41
f
⁢
Y
11
d
⁢
Y
opt
+
Y
31
f
⁢
Y
44
f
⁢
Y
11
d
⁢
Y
opt
+
Y
24
f
⁢
Y
32
f
⁢
Y
21
d
⁢
Y
opt
-
Y
21
f
⁢
Y
44
f
⁢
Y
21
d
⁢
Y
opt
)
(
Y
23
f
⁢
Y
31
f
⁢
Y
21
d
-
Y
21
f
⁢
Y
33
f
⁢
Y
21
d
+
Y
31
f
⁢
Y
12
d
⁢
Y
21
d
-
Y
22
f
⁢
Y
31
f
⁢
Y
22
d
+
Y
21
f
⁢
Y
32
f
⁢
Y
22
d
-
Y
31
f
⁢
Y
11
d
⁢
Y
22
d
-
Y
22
f
⁢
Y
31
f
⁢
Y
opt
+
Y
21
f
⁢
Y
32
f
⁢
Y
opt
-
Y
31
f
⁢
Y
11
d
⁢
Y
opt
+
Y
21
f
⁢
Y
21
d
⁢
Y
opt
)
to match the admittance value, where Ymnf, (m, nεN, 1≦m, n≦4) are 4-port admittance matrix parameters of said 4-port feedback circuit, Y21d (m, nεN, 1≦m, n≦2) are 2-port admittance matrix parameters of said power transistor, YL is a load admittance at the maximum output power, and Yopt is the admittance at the output terminal of said power transistor.

514 more elements

Facts

Application

12/213,613Filed 23 Jun 2008 · continuation

Priority

TW 95134587 A19 Sep 2006

Published

US 2009/0009255 A18 Jan 2009

Granted

8 Jun 2010

Term ends

Not estimatedThe source records don’t support an estimate.

Classification17 codes

H03F 1/34
Details of amplifiers with only discharge tubes, only semiconductor devices or only unspecified devices as amplifying elements:…
H03F 1/26
Details of amplifiers with only discharge tubes, only semiconductor devices or only unspecified devices as amplifying elements: modifications of…
H03F 1/301
Modifications of amplifiers to reduce influence of variations of temperature or supply voltage or other physical parameters: in MOSFET amplifiers
H03F 1/56
Details of amplifiers with only discharge tubes, only semiconductor devices or only unspecified devices as amplifying elements: modifications of…

Family

Application11/621,793Parent of this continuation · filed 10 Jan 2007

US 2009/0009255 A1Pre-grant publication · published 8 Jan 2009

US 7,439,802 B2Parent of this continuation

US 2008/0068077 A1Published application

US 7,733,173 B2This patent

From the US filing history. Foreign family members aren’t listed.

Abstract

Claims6