TWM593695U - Inconsistency bias power amplifier - Google Patents

Abstract

A non-uniform bias power amplifier is suitable for being disposed between a power input terminal and a power output terminal. It includes a first amplifying circuit and a second amplifying circuit. The first amplifier circuit is electrically connected to the power input terminal. The second amplifier circuit is disposed between the first amplifier circuit and the power output terminal, and is electrically connected to the first amplifier circuit and the power output terminal, respectively. Wherein, the bias quiescent current of the transistor in the first amplifier circuit is greater than the bias quiescent current of the transistor in the second amplifier circuit, which further enhances the inconsistency Power Added Efficiency of a power amplifier with a bias voltage.

Description

Non-uniform bias power amplifier

The present invention relates to a power amplifier, especially a non-uniform bias power amplifier used for multi-stage power amplifier to improve the additional power efficiency.

At present, the power amplifier or power amplifier circuit used in the wireless communication industry, in order to improve the power additional efficiency, the bias voltage of the transistor inside the power amplifier uses the class-AB (class-AB) bias method to improve the power additional efficiency .

Refer to FIG. 1 for the characteristic curve of class A amplifier, where _IC is the collector current, V _CE is the collector voltage, I _BQ is the input signal, I _CQ is the output signal, and Q is the bias static Working point, L is the load line. The area of the static operating point Q of the class A amplifier is at 50% saturation current. The class A amplifier always operates in the linear region and has better linear amplification efficiency, but consumes more power.

Refer to FIG. 2 for the characteristic curve of class B amplifier, where _IC is the collector current, V _CE is the collector voltage, I _BQ is the input signal, I _CQ is the output signal, and Q is the bias static Working point. Class B amplifiers have a static operating point Q at 0% saturation current. Compared with class A amplifiers, class B amplifiers have lower power consumption, but class B amplifiers are prone to crossover distortion.

Refer to FIG. 3 for the characteristic curve of class AB amplifier, where _IC is the collector current, V _CE is the collector voltage, I _BQ is the input signal, I _CQ is the output signal, and Q is the bias static Working point. Class AB amplifiers have a static operating point Q around 20% saturation current. Class AB amplifiers provide a good compromise between linearity and power consumption.

When the power amplifier circuit is operating, if there are input signals, these signals are amplified and output to other external devices. The voltage used when the power amplifier circuit processes signal amplification is called the operating voltage, and the current used is called the operating current. When the input of the power amplifier device is in a no-signal state, at this time we define the basic current lost in this state as "Quiescent Current", also known as the bias static operating current.

At present, multi-stage power amplifiers composed of common emitters use the same type of transistors in each stage of the amplifier circuit. For example, the common-emitter multi-stage power amplifiers composed of class AB amplifiers each stage of the amplifier circuit All belong to class AB amplifier circuit.

In addition, in the cascade multi-stage power amplifier composed of the same type of amplifier circuit, the size of the transistor in the amplifier circuit near the input terminal is smaller, and the size of the transistor in the amplifier circuit closer to the output terminal is larger. The size of the crystal can be expressed by the emitter area in the transistor, and the closer to the output terminal, the larger the quiescent current "Quiescent Current" of the transistor, resulting in the ineffectiveness of the power added efficiency of the current multi-stage power amplifier. Promote.

The current wireless transmission specifications have strict requirements on linearity to correspond to the amplitude and phase distortion. Among them, the RF power amplifier is the most critical part of the transmitter, but for the improvement of transmission speed, the current RF power amplifier may show insufficient linearity performance.

When the output power of a high-efficiency RF power amplifier is greater than 100mW, providing an error vector magnitude (EVM) of -35dB is a challenging task, especially when it is necessary to eliminate the dependence on digital predistortion to reduce cost and system pressure. Moreover, it has enough output power and provides an error vector magnitude (EVM) of -47dB, which is beneficial to the transmission of wireless information. Because the transistor The scaling of technology and the reduction of the power supply voltage have forced the output power to be limited to reach the watt-level saturation power.

There are currently many technologies to cope with the above challenges, such as capacitance compensation technology based on P-type metal oxide semiconductor field effect transistors, multi-gated transistors, or adaptive deviation technology, which are not sufficient to achieve an error vector magnitude (EVM) Frequency and power levels change.

Therefore, how to improve the power-added efficiency of the power amplifier to cope with the high-speed transmission rate and overcome the existing linearization limitations is a goal urgently needed by relevant technical personnel.

In view of this, the purpose of the present invention is to provide a non-uniform bias power amplifier, which is suitable for being disposed between a power input terminal and a power output terminal. The non-uniform bias power amplifier It includes a first amplifier circuit and a second amplifier circuit.

The first amplifier circuit is electrically connected to the power input terminal. The second amplifier circuit is disposed between the first amplifier circuit and the power output terminal, and is electrically connected to the first amplifier circuit and the power output terminal, respectively.

Wherein, the bias quiescent current of the transistor in the first amplifier circuit is greater than the bias quiescent current of the transistor in the second amplifier circuit.

Another technical means of the present invention is that the above-mentioned first amplifying circuit includes a first transistor composed of a first base terminal, a first collector terminal, and a first emitter terminal, and a first impedance matching Circuit, a first base bias circuit, and a first collector bias circuit, the One end of the first impedance matching circuit is electrically connected to the power input terminal, and the other end of the first impedance matching circuit is electrically connected to the first base terminal of the first transistor and one end of the first base bias circuit, The other end of the first base bias circuit is electrically connected to a first base voltage, one end of the first collector bias circuit is electrically connected to the first collector terminal of the first transistor, the first The other end of the collector bias circuit is electrically connected to a first collector voltage, and the first emitter terminal is grounded.

Another technical means of the present invention is that the above-mentioned second amplifying circuit includes a second transistor composed of a second base terminal, a second collector terminal, and a second emitter terminal, and a second impedance matching A circuit, a second base bias circuit, and a second collector bias circuit, one end of the second impedance matching circuit is electrically connected to the first collector terminal of the first transistor, and the second impedance is matched The other end of the circuit is electrically connected to the second base terminal of the second transistor and one end of the second base bias circuit, and the other end of the second base bias circuit is electrically connected to a second base voltage Connected, one end of the second collector bias circuit is electrically connected to the second collector terminal of the second transistor and the power output terminal, and the other end of the second collector bias circuit is connected to a second collector The voltage is electrically connected and the second emitter is grounded.

A further technical means of the present invention is that the non-uniform bias power amplifier described above further includes a third amplifying circuit, which is arranged between the second amplifying circuit and the power output terminal, and is respectively amplified with the second The circuit and the power output terminal are electrically connected.

Another technical means of the present invention is that the non-uniform bias power amplifier described above further includes a fourth amplifying circuit, which is disposed between the third amplifying circuit and the power output terminal, and is respectively amplified with the third The circuit and the power output terminal are electrically connected.

Another technical means of the present invention is that the bias static working current of the transistor in the third amplifying circuit is larger than the bias static working current of the transistor in the fourth amplifying circuit.

Another technical means of the present invention is that the non-uniform bias power amplifier described above further includes a fifth amplifier circuit, which is disposed between the power input terminal and the first amplifier circuit, and is respectively connected to the power input terminal And the first amplifier circuit is electrically connected.

Another technical means of the present invention is that the non-uniform bias power amplifier described above further includes a sixth amplifier circuit, which is disposed between the fifth amplifier circuit and the first amplifier circuit, and is separately connected to the fifth The amplifier circuit and the first amplifier circuit are electrically connected.

Another technical means of the present invention is that the non-uniform bias power amplifier described above further includes a seventh amplifier circuit, which is disposed between the second amplifier circuit and the power output terminal, and is separately amplified from the second amplifier The circuit and the power output terminal are electrically connected.

Another technical means of the present invention is that the above-mentioned first amplifying circuit has a bias static working current between 1% and 95% saturation current, and the second amplifying circuit has a bias static working current between 0% and 15 % Saturation current.

The beneficial effect of the present invention is that the bias static working current of the first transistor of the first amplifier circuit is close to the saturation current, and the bias static working current of the second transistor of the second amplifier circuit is close to the cut-off current, both It cannot be used alone in high-speed power amplifiers with high-speed information transmission, but the first amplifier circuit disclosed in the present invention is installed at or near the power input terminal, and the second amplifier circuit is installed at or near the power output terminal When the first amplifier circuit and the second amplifier circuit are directly electrically connected, it can be used in a high-amplitude power amplifier for super-speed information transmission. In addition, the transistor bias of the first amplifier circuit works statically The current is larger than the transistor bias static working current of the second amplifying circuit, which is different from the traditional multi-stage power amplifier in that the static working current of the first-stage and one-stage bias voltage is gradually increased. The new type can effectively increase the additional power efficiency.

I _C ‧‧‧ Collector current

V _CE ‧‧‧ Collector voltage

I _BQ ‧‧‧ input signal

I _CQ ‧‧‧ output signal

Q‧‧‧static working point

L‧‧‧Load line

RF_IN‧‧‧Power input

RF_OUT‧‧‧Power output

VB1‧‧‧First base voltage

VC1‧‧‧First collector voltage

VB2‧‧‧Second base voltage

VC2‧‧‧Second collector voltage

VB3‧‧‧third base voltage

VC3‧‧‧third collector voltage

VB4‧‧‧ Fourth base voltage

VC4‧‧‧ Fourth collector voltage

VCE‧‧‧ Collector voltage

IC‧‧‧ Collector current

IS‧‧‧saturation current

Q1‧‧‧bias static working current

Q2‧‧‧bias static working current

G‧‧‧Ground

3‧‧‧First amplifier circuit

31‧‧‧ First transistor

311‧‧‧The first base extreme

312‧‧‧ Episode 1 Extreme

313‧‧‧The first shot extreme

32‧‧‧First impedance matching circuit

33‧‧‧First base bias circuit

34‧‧‧The first collector bias circuit

4‧‧‧ Second amplifier circuit

41‧‧‧Second transistor

411‧‧‧The second base extreme

412‧‧‧ Episode 2 Extreme

413‧‧‧Second shot extreme

42‧‧‧Second impedance matching circuit

43‧‧‧Second base bias circuit

44‧‧‧Second collector bias circuit

53‧‧‧The third amplifier circuit

531‧‧‧The third transistor

532‧‧‧The third impedance matching circuit

533‧‧‧ Third base bias circuit

534‧‧‧Third collector bias circuit

54‧‧‧ Fourth Amplifier Circuit

541‧‧‧ fourth transistor

542‧‧‧ Fourth impedance matching circuit

543‧‧‧ fourth base bias circuit

544‧‧‧ Fourth collector bias circuit

55‧‧‧ fifth amplifier circuit

56‧‧‧Sixth amplifier circuit

57‧‧‧Seventh amplifier circuit

Fig. 1 is a schematic diagram of a characteristic curve illustrating the characteristic curve of a conventional class A amplifier (class-A); Fig. 2 is a schematic diagram of a characteristic curve illustrating the characteristic curve of a conventional class B amplifier (class-B); Fig. 3 Is a characteristic curve diagram illustrating the characteristic curve of a conventional class-AB amplifier; FIG. 4 is a schematic circuit diagram, which is a first preferred embodiment of a new type of non-uniform bias power amplifier; FIG. 5 is a characteristic curve diagram illustrating the characteristic curve of the first amplification circuit of the first preferred embodiment; FIG. 6 is a characteristic curve diagram illustrating the characteristic curve of the second amplification circuit of the first preferred embodiment FIG. 7 is a circuit schematic diagram, a second preferred embodiment of a non-uniform bias power amplifier of the present invention; FIG. 8 is a circuit schematic diagram, a third preferred of a non-uniform bias power amplifier of the present invention; Example; 9 is a schematic circuit diagram of a fourth preferred embodiment of a non-uniform bias power amplifier of the present invention; FIG. 10 is a schematic circuit diagram of a fifth preferred implementation of a non-uniform bias power amplifier of the present invention Example; FIG. 11 is a schematic circuit diagram, a sixth preferred embodiment of the novel non-uniform bias power amplifier; and FIG. 12 is a schematic circuit diagram, the seventh of a novel non-uniform bias power amplifier. Preferred embodiment.

Relevant patent application features and technical content of the new model will be clearly presented in the following detailed description with reference to the seven preferred embodiments of the drawings. Before making a detailed description, it should be noted that similar elements are represented by the same number.

Referring to FIGS. 4, 5, and 6, it is a first preferred embodiment of a new type of non-uniform bias power amplifier. The non-uniform bias power amplifier is suitable for being disposed at a power input terminal RF_IN and a power output terminal RF_OUT. In between, the non-uniform bias power amplifier includes a first amplifying circuit 3 and a second amplifying circuit 4.

The first amplifier circuit 3 is electrically connected to the power input terminal RF_IN. The second amplifying circuit 4 is disposed between the first amplifying circuit 3 and the power output terminal RF_OUT, and is electrically connected to the first amplifying circuit 3 and the power output terminal RF_OUT, respectively. The transistor in the first amplifying circuit 3 The bias static working current Q1 is greater than the bias static working current Q2 of the transistor in the second amplifier circuit 4.

Recalling FIG. 5, VCE is the collector voltage, IC is the collector current, IS is the saturation current, L is the load line of 50% saturation current IS, and Q1 is the bias static operating current of the first amplifier circuit 3. Wherein, the bias static working current Q1 of the first amplifying circuit 3 is between 1% and 95% saturation current IS.

Recalling FIG. 6, where VCE is the collector voltage, IC is the collector current, IS is the saturation current, L is the load line of 50% saturation current IS, and Q2 is the bias static operating current of the second amplifier circuit 4. The bias static operating current Q2 of the second amplifying circuit 4 is between 0% and 15% of the saturation current IS, that is, the bias static operating current Q2 of the second amplifying circuit 4 is close to the cut-off current.

The first amplifier circuit 3 includes a first transistor 31 composed of a first base terminal 311, a first collector terminal 312, and a first emitter terminal 313, a first impedance matching circuit 32, and a first A base bias circuit 33, and a first collector bias circuit 34, one end of the first impedance matching circuit 32 is electrically connected to the power input terminal RF_IN, and the other end of the first impedance matching circuit 32 is connected to the The first base terminal 311 of the first transistor 31 is electrically connected to one end of the first base bias circuit 33, and the other end of the first base bias circuit 33 is electrically connected to a first base voltage VB1 , One end of the first collector bias circuit 34 is electrically connected to the first collector terminal 312 of the first transistor 31, and the other end of the first collector bias circuit 34 is connected to a first collector voltage VC1 Electrically connected, the first emitter terminal 313 is grounded G.

The second amplifying circuit 4 includes a second transistor 41 composed of a second base terminal 411, a second collector terminal 412, and a second emitter terminal 413, a second impedance matching circuit 42, and a second A base bias circuit 43 and a second collector bias circuit 44, one end of the second impedance matching circuit 42 is electrically connected to the first collector terminal 312 of the first transistor 31, the second impedance is matched The other end of the circuit 42 is electrically connected to the second base terminal 411 of the second transistor 41 and one end of the second base bias circuit 43. The other end of the second base bias circuit 43 is connected to a first Two base voltage VB2 Connected, one end of the second collector bias circuit 44 is electrically connected to the second collector terminal 412 of the second transistor 41 and the power output terminal RF_OUT, and the other end of the second collector bias circuit 44 is connected to A second collector voltage VC2 is electrically connected, and the second emitter terminal 413 is grounded G.

The transistor used in the first amplifier circuit 3 and the second amplifier circuit 4 is selected from one of bipolar junction transistor (BJT) and field-effect transistor (FET) And combinations.

Among them, SiGe (Silicon Gemanium) BJT, GaAs (Galium Arsnide) HBT (Heterojunction bipolar transistor), etc. can be used for the bipolar junction transistor (BJT). As the field effect transistor (FET), CMOS (Complementary metal-oxide-semiconductor) FET, pHEMT (pseudomorphic heterostructure High-electron-mobility transistor) FET, GaN (Galium Nitrde) FET, etc. can be used.

The new creator of this case should emphasize that the power amplifiers used in today's digital personal communication systems have very strict linearity requirements. The traditional analog modulation system in today's digital systems has a large signal transmission error rate. , Its system has been unable to work properly, and even disconnected.

At present, the transistors used in high linear power amplifiers are all class-AB amplifiers, which can improve the power added efficiency (PAE) of the power amplifiers. Among them, the characteristic of the multi-stage power amplifier is that the quiescent operating current of the collector bias of the transistor close to the input end is smaller than the quiescent operating current of the collector bias of the transistor close to the output end. For example, in a three-stage power amplifier, the quiescent operating current of the collector bias of the first-stage transistor is less than the quiescent operating current of the collector bias of the second-stage transistor. The collector-biased quiescent operating current of the first-level transistor is less than the collector-biased static operating current of the third-level transistor.

The bias static operating current Q1 of the first transistor 31 of the first amplifying circuit 3 disclosed by the present invention is close to the saturation current IS, which is a transistor with poor linear amplification efficiency, and the first amplifying circuit 3 cannot be used alone for high In an amplifier for linearity information transmission; the biased static operating current Q2 of the second transistor 41 of the second amplifier circuit 4 is close to the cut-off current, which is also a transistor with poor linear amplification efficiency, and the second amplifier circuit 4 cannot Used alone in information transmission amplifiers with high linearity.

Since the first amplifier circuit 3 of the non-uniform bias power amplifier is disposed in front of the second amplifier circuit 4, the collector bias static operating current Q1 of the first transistor 31 in the first amplifier circuit 3 will be greater than the second amplifier The collector of the second transistor 41 in the circuit 4 biases the quiescent operating current.

For example, when traditional multi-stage power amplifiers use class A amplifiers (class-A), the emitter area of the class A transistor in the traditional first-stage amplifier circuit uses 240 μm ² and a collector voltage of 5 V is applied. The quiescent operating current of the Class A transistor in the first-stage amplifier circuit is 36mA; the emitter area of the Class A transistor in the traditional second-stage amplifier circuit uses 1440μm ² and a collector voltage of 5V is applied. The quiescent operating current of the Class A transistor in the amplifier circuit is 216mA.

Although the emitter area of the first transistor 31 of the first amplifying circuit 3 of the novel non-uniform bias power amplifier also uses 240 μm ² and applies a collector voltage of 5 V, the first amplifying circuit 3 has the first The bias static current Q1 of the transistor 31 is 50mA; although the emitter area of the second transistor 41 of the second amplifying circuit 4 of the non-uniform bias power amplifier of the new type also uses 1440μm ² , and a 5V collector is applied Voltage, but the quiescent operating current Q2 of the second transistor 41 of the second amplifier circuit 4 is 15 mA.

From the above description, the same transistor size of the present novel non-uniformity of the bias of the power amplifier (emitter area) of the conventional set of getting a large (240μm ² <1440μm ^2, lifting 6-fold), but the first amplifier circuit The bias static operating current Q1 of the first transistor 31 of 3 is larger than the bias static operating current (50mA>36mA) of the first transistor of the traditional multi-stage power amplifier; the second transistor of the second amplifier circuit 4 The bias quiescent operating current Q2 of 41 is smaller than the bias quiescent operating current (15mA<216mA) of the second-stage transistor of the traditional multi-stage power amplifier.

In addition, the static quiescent operating current of each stage transistor of the traditional multistage power amplifier is gradually increasing (36mA→216mA). The static bias current of each stage transistor of the new non-uniform bias power amplifier The working current is gradually decreasing (50mA→15mA), and its bias static working current is reduced by about 0.3 times (15mA/50mA=0.3).

Therefore, the novel non-uniform bias power amplifier operates the bias static operating current Q1 of the first transistor 31 of the first amplifier circuit 3 in the direction of saturation current, and the second transistor 41 of the second amplifier circuit 4 When the bias quiescent operating current Q2 is operated in the cut-off current direction or the current direction of the Class B amplifier, the bias quiescent operating current Q1 of the first transistor 31 is greater than the bias quiescent operating current Q2 of the second transistor 41.

The values used in the above examples are only the values measured or calculated by one of the circuit settings of the first preferred embodiment. In actual implementation, the circuit design should be based on the power amplifier actually used. The calculated values should be different and should not be limited to the examples of the preferred embodiment.

Referring to FIG. 7, it is a second preferred embodiment of a non-uniform bias power amplifier of the present invention. The second preferred embodiment is substantially the same as the first preferred embodiment, and the same is not described in detail here. The difference is that the non-uniform bias power amplifier further includes a third amplifying circuit 53.

The third amplifier circuit 53 is disposed between the second amplifier circuit 4 and the power output terminal RF_OUT, and is electrically connected to the second base terminal 412 of the second amplifier circuit 4 and the power output terminal RF_OUT, respectively. Wherein, the third amplifying circuit 53 may be any kind of power amplifying circuit, and then the combination of the first amplifying circuit 3 and the second amplifying circuit 4 is used to improve the power added efficiency of the non-uniform bias power amplifier.

Referring to FIG. 8, it is a third preferred embodiment of a non-uniform bias power amplifier of the present invention. The third preferred embodiment is substantially the same as the second preferred embodiment, and the same is not described in detail here. The difference is that the non-uniform bias power amplifier further includes a fourth amplifying circuit 54.

The fourth amplifier circuit 54 is disposed between the third amplifier circuit 53 and the power output terminal RF_OUT, and is electrically connected to the third amplifier circuit 53 and the power output terminal RF_OUT, respectively. Wherein, the fourth amplifying circuit 54 may be any kind of power amplifying circuit, and then the combination of the first amplifying circuit 3 and the second amplifying circuit 4 is used to improve the power added efficiency of the non-uniform bias power amplifier.

Referring to FIG. 9, it is a fourth preferred embodiment of a non-uniform bias power amplifier of the present invention. The fourth preferred embodiment is substantially the same as the third preferred embodiment, and the same will not be described in detail here. The difference is that the third transistor 531 of the third amplifier circuit 53 of the non-uniform bias power amplifier biases the quiescent operating current to the first transistor 31 of the first amplifier circuit 3 Similarly, the third transistor 531 of the third amplifying circuit 53 biases the static operating current between 1% and 95% of the saturation current, and the fourth transistor 541 of the fourth amplifying circuit 54 biases the static operating current and the second The second transistor 41 of the amplifier circuit 4 is the same. The fourth transistor 541 of the fourth amplifier circuit 54 biases the static operating current between 0% and 15% of the saturation current. The fourth transistor 541 of the fourth amplifier circuit 54 The biased quiescent operating current is close to the cut-off current.

The third amplifying circuit 53 has a third transistor 531, a third impedance matching circuit 532, a third base bias circuit 533, and a third collector bias circuit 534, the third impedance matching One end of the circuit 532 is electrically connected to the first collector terminal 312 of the second transistor 41, the third transistor 531 is electrically connected to the other end of the third impedance matching circuit 532, and the third base bias circuit 533 One end is electrically connected to the third transistor 531 and the third impedance matching circuit 532, the other end of the third base bias circuit 533 is electrically connected to a third base voltage VB3, and the third collector is biased One end of the voltage circuit 534 is electrically connected to the third transistor 531, the other end of the third collector bias circuit 534 is electrically connected to a third collector voltage VC3, and the third transistor 531 is grounded G.

The fourth amplifying circuit 54 has a fourth transistor 541, a fourth impedance matching circuit 542, a fourth base bias circuit 543, and a fourth collector bias circuit 544, the fourth impedance matching One end of the circuit 542 is electrically connected to the third transistor 531, the fourth transistor 541 is electrically connected to the other end of the fourth impedance matching circuit 542, and one end of the fourth base bias circuit 543 is connected to the fourth The transistor 541 and the fourth impedance matching circuit 542 are electrically connected, the other end of the fourth base bias circuit 543 is electrically connected to a fourth base voltage VB4, and one end of the fourth collector bias circuit 544 It is electrically connected to the fourth transistor 541 and the power output terminal RF_OUT, the other end of the fourth collector bias circuit 544 is electrically connected to a fourth collector voltage VC4, and the fourth transistor 541 is grounded G.

Referring to FIG. 10, it is a fifth preferred embodiment of a non-uniform bias power amplifier of the present invention. The fifth preferred embodiment is substantially the same as the first preferred embodiment, and the same is not described in detail here. The difference is that the non-uniform bias power amplifier further includes a fifth amplifying circuit 55.

The fifth amplifier circuit 55 is disposed between the power input terminal RF_IN and the first amplifier circuit 3, and is electrically connected to the power input terminal RF_IN and the first impedance matching circuit 32 of the first amplifier circuit 3, respectively. The fifth amplifying circuit 55 may be any kind of power amplifying circuit, and the combination of the first amplifying circuit 3 and the second amplifying circuit 4 is used to improve the power added efficiency of the non-uniform bias power amplifier.

Referring to FIG. 11, it is a sixth preferred embodiment of a non-uniform bias power amplifier of the present invention. The sixth preferred embodiment is substantially the same as the fifth preferred embodiment, and the same is not described in detail here. The difference is that the non-uniform bias power amplifier further includes a sixth amplifier circuit 56.

The sixth amplifier circuit 56 is disposed between the fifth amplifier circuit 55 and the first amplifier circuit 3, and is electrically connected to the fifth amplifier circuit 55 and the first impedance matching circuit 32 of the first amplifier circuit 3, respectively. The sixth amplifying circuit 56 may be any kind of power amplifying circuit, and the combination of the first amplifying circuit 3 and the second amplifying circuit 4 is used to improve the power added efficiency of the non-uniform bias power amplifier.

Referring to FIG. 12, it is a seventh preferred embodiment of a non-uniform bias power amplifier of the present invention. The seventh preferred embodiment is substantially the same as the fifth preferred embodiment, and the same is not described in detail here. The difference is that the non-uniform bias power amplifier further includes a seventh amplifying circuit 57.

The seventh amplifier circuit 57 is disposed between the second amplifier circuit 4 and the power output terminal RF_OUT, and is electrically connected to the second emitter terminal 413 of the second amplifier circuit 4 and the power output terminal RF_OUT, respectively. The seventh amplifying circuit 57 may be any kind of power amplifying circuit, and then the combination of the first amplifying circuit 3 and the second amplifying circuit 4 is used to improve the power added efficiency of the non-uniform bias power amplifier.

It is worth mentioning that the new model proposes a highly linear common emitter type non-uniform bias power amplifier, which is used in the transmission circuit of the wireless local area network and is configured in parallel cascade into two and three. The power amplifiers of four stages, four stages, and even more are used to eliminate the third and fifth intermodulation distortion, and the third harmonic distortion due to the nonlinearity of the drain-source current.

The new type can be used to improve the phase distortion and the power added efficiency of high power output. In the output frequency of 5.15GHz, the non-uniform bias power amplifier has quadrature amplitude modulation signal source without phase distortion. Its output power meets strict linearity, and the error vector amplitude of -35dB is 17.8, 17.3, and 17.6dBm, respectively.

It can be seen from the above description that the novel non-uniform bias power amplifier does have the following effects:

1. Increasing power additional efficiency: the bias static operating current Q1 of the first transistor 31 of the first amplifier circuit 3 operates in the direction of bias saturation current, and the bias voltage static operation of the second transistor 41 of the second amplifier circuit 4 When the current Q2 is operated in the bias cut-off current direction or the current direction of the class B amplifier, the bias static operating current Q1 of the first transistor 31 is greater than the bias static operating current Q2 of the second transistor 41. "Current" can further improve the power added efficiency (Power Added Efficiency).

Second, it can be matched with other amplifier circuits: the non-uniform bias power amplifier of the present invention can be used not only as a second-level bias power amplifier, but also with other amplifier circuits to form a three-level or four-level, or More grades of non-uniform bias power amplifiers are used as radio frequency power amplifiers in wireless transmission circuits.

In summary, the present invention discloses a new combination of amplifier circuits, which cannot be used alone in the transistors of linear power amplifiers. The combination forms a cascode multi-stage power amplifier, which can not only reduce the bias static operating current "Quiescent Current" further enhances the power added efficiency, and can be used with other power amplifier circuits for regional wireless transmission devices, so it can really achieve the purpose of new cost.

However, the above are only the seven preferred embodiments of the new model. When this cannot be used to limit the scope of the implementation of the new model, that is, the simple equivalent changes made by the patent application scope of the new model and the description of the new model Modifications are still covered by this new patent.

RF_IN‧‧‧Power input

RF_OUT‧‧‧Power output

VB1‧‧‧First base voltage

VC1‧‧‧First collector voltage

VB2‧‧‧Second base voltage

VC2‧‧‧Second collector voltage

G‧‧‧Ground

3‧‧‧First amplifier circuit

31‧‧‧ First transistor

311‧‧‧The first base extreme

312‧‧‧ Episode 1 Extreme

313‧‧‧The first shot extreme

32‧‧‧First impedance matching circuit

33‧‧‧First base bias circuit

34‧‧‧The first collector bias circuit

4‧‧‧ Second amplifier circuit

41‧‧‧Second transistor

411‧‧‧The second base extreme

412‧‧‧ Episode 2 Extreme

413‧‧‧Second shot extreme

42‧‧‧Second impedance matching circuit

43‧‧‧Second base bias circuit

44‧‧‧Second collector bias circuit

Claims (10)

A non-uniform bias power amplifier, suitable for setting between a power input terminal and a power output terminal, and comprising: a first amplifier circuit electrically connected to the power input terminal; and a second amplifier circuit, set Between the first amplifying circuit and the power output terminal, and electrically connected to the first amplifying circuit and the power output terminal respectively; wherein, the bias static working current of the transistor in the first amplifying circuit is greater than the second The quiescent operating current of the transistor in the amplifier circuit. The non-uniform bias power amplifier according to item 1 of the patent application scope, wherein the first amplifying circuit includes a first composed of a first base terminal, a first collector terminal, and a first emitter terminal A transistor, a first impedance matching circuit, a first base bias circuit, and a first collector bias circuit, one end of the first impedance matching circuit is electrically connected to the power input terminal, the first The other end of the impedance matching circuit is electrically connected to the first base terminal of the first transistor and one end of the first base bias circuit, and the other end of the first base bias circuit is connected to a first base Voltage is electrically connected, one end of the first collector bias circuit is electrically connected to the first collector terminal of the first transistor, and the other end of the first collector bias circuit is electrically connected to a first collector voltage , The first emitter is grounded. The non-uniform bias power amplifier according to item 1 of the patent application scope, wherein the second amplifying circuit includes a second base consisting of a second base terminal, a second collector terminal, and a second emitter terminal Transistor, a second impedance matching circuit, a second base bias circuit, and a second collector bias circuit, the second impedance matching circuit One end of the circuit is electrically connected to the first collector terminal of the first transistor, and the other end of the second impedance matching circuit is electrically connected to the second base terminal of the second transistor and one end of the second base bias circuit Connected, the other end of the second base bias circuit is electrically connected to a second base voltage, one end of the second collector bias circuit is connected to the second collector terminal of the second transistor and the power output The terminal is electrically connected, the other end of the second collector bias circuit is electrically connected to a second collector voltage, and the second emitter terminal is grounded. According to the non-uniform bias power amplifier described in item 1 of the patent application scope, it further includes a third amplifying circuit, which is arranged between the second amplifying circuit and the power output terminal, and is respectively connected to the second amplifying circuit and the The power output is electrically connected. The non-uniform bias power amplifier according to item 4 of the patent application scope further includes a fourth amplifying circuit, which is disposed between the third amplifying circuit and the power output terminal, and is respectively connected to the third amplifying circuit and the The power output is electrically connected. The non-uniform bias power amplifier according to item 5 of the patent application scope, wherein the bias static operating current of the transistor in the third amplifier circuit is greater than the bias static operating current of the transistor in the fourth amplifier circuit. The non-uniform bias power amplifier according to item 1 of the patent application scope further includes a fifth amplifying circuit, which is arranged between the power input terminal and the first amplifying circuit, and is respectively connected to the power input terminal and the first An amplifier circuit is electrically connected. According to the non-uniform bias power amplifier described in item 7 of the patent application scope, it further includes a sixth amplifying circuit, which is arranged between the fifth amplifying circuit and the first amplifying circuit, and is respectively connected to the fifth amplifying circuit and the The first amplifier circuit is electrically connected. According to the non-uniform bias power amplifier described in item 1 of the patent application scope, it further includes a seventh amplifying circuit, disposed between the second amplifying circuit and the power output terminal, and separately connected to the second amplifying circuit and the The power output is electrically connected. According to the non-uniform bias power amplifier described in item 1 of the patent application range, wherein the first quiescent circuit has a quiescent bias operating current between 1% and 95% saturation current, and the second amp circuit has a bias static operation The current is between 0% and 15% saturation current.

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