Patent ID: 12191832

DETAILED DESCRIPTION OF THE EMBODIMENTS

The specific embodiment of the present disclosure will be described below so that those skilled in the art can understand the present disclosure, but it should be clear that the present disclosure is not limited to the scope of the specific embodiment. For those of ordinary skill in the art, as long as various changes fall within the spirit and scope of the present disclosure defined and determined by the appended claims, these changes are apparent, and all inventions and creations using the concept of the present disclosure are protected.

As shown inFIG.1, an LMBA based on a variable XCP includes an ADB circuit, a first balance terminal amplifier module, a second balance terminal amplifier module, a control terminal amplifier module, a first driver amplifier module, a second driver amplifier module, a third driver amplifier module, a variable XCP, resistor R5, resistor R6, 90-degree differential coupler Q1, 90-degree differential coupler Q2, and 90-degree differential coupler Q3.

An input terminal of the ADB circuit and a third input terminal of the 90-degree differential coupler Q1each serve as an input terminal of an amplifier. One terminal of an isolated terminal of the 90-degree differential coupler Q1is connected to the other terminal of the isolated terminal of the 90-degree differential coupler Q1through the resistor R5. A pass-through terminal of the 90-degree differential coupler Q1includes one terminal connected to a first input terminal of the 90-degree differential coupler Q2, and the other terminal connected to a second input terminal of the 90-degree differential coupler Q2. One terminal of an isolated terminal of the 90-degree differential coupler Q2is connected to the other terminal of the isolated terminal of the 90-degree differential coupler Q2through the resistor R6. A third output terminal of the 90-degree differential coupler Q1is connected to an input terminal of the third driver amplifier module. An output terminal of the third driver amplifier module is connected to an input terminal of the control terminal amplifier module. A coupling terminal of the 90-degree differential coupler Q2includes one terminal connected to a first input terminal of the first driver amplifier module, and the other terminal connected to a second input terminal of the first driver amplifier module. A pass-through terminal of the 90-degree differential coupler Q2includes one terminal connected to a first input terminal of the second driver amplifier module, and the other terminal connected to a second input terminal of the second driver amplifier module. An output terminal of the first driver amplifier module is connected to an input terminal of the first balance terminal amplifier module. An output terminal of the second driver amplifier module is connected to an input terminal of the second balance terminal amplifier module. A first output terminal and a second output terminal of the first balance terminal amplifier module are respectively connected to one terminal of a pass-through terminal of the 90-degree differential coupler Q3and the other terminal of the pass-through terminal of the 90-degree differential coupler Q3. The second balance terminal amplifier module includes a first output terminal connected to one terminal of a coupling terminal of the 90-degree differential coupler Q3, and a second output terminal connected to the other terminal of the coupling terminal of the 90-degree differential coupler Q3. An output terminal of the control terminal amplifier module is connected to an isolated terminal of the 90-degree differential coupler Q3. An output terminal of the 90-degree differential coupler Q3serves as an output terminal of the millimeter-wave LMBA based on the variable XCP.

The first driver amplifier module includes transformer Xfrm1and driver amplifier DA1. A primary side of the transformer Xfrm1serves as an input terminal of the first driver amplifier module. A secondary side of the transformer Xfrm1includes a first terminal connected to a first input terminal of the driver amplifier DA1, a second terminal connected to a second input terminal of the driver amplifier DA1, and a third terminal connected to an output terminal of the ADB circuit. A first output terminal and a second output terminal of the driver amplifier DA1are connected to the first balance terminal amplifier module.

The second driver amplifier module includes transformer Xfrm2and driver amplifier DA2. A primary side of the transformer Xfrm2serves as an input terminal of the second driver amplifier module. A secondary side of the transformer Xfrm2includes a first terminal connected to a first input terminal of the driver amplifier DA2, a second terminal connected to a second input terminal of the driver amplifier DA2, and a third terminal connected to the output terminal of the ADB circuit. A first output terminal and a second output terminal of the driver amplifier DA2are connected to the second balance terminal amplifier module.

The third driver amplifier module includes transformer Xfrm3and driver amplifier DA3. A primary side of the transformer Xfrm3serves as an input terminal of the third driver amplifier module. A secondary side of the transformer Xfrm3includes one terminal connected to a first input terminal of the driver amplifier DA3, and the other terminal connected to a second input terminal of the driver amplifier DA3. A first output terminal and a second output terminal of the driver amplifier DA3are connected to the variable XCP.

The first balance terminal amplifier module includes balance terminal amplifier BA1, transformer Xfmr4, and transformer Xfmr7. A primary side of the transformer Xfmr4serves as an input terminal of the first balance terminal amplifier module. A secondary side of the transformer Xfmr4includes a first terminal connected to a first input terminal of the balance terminal amplifier BA1, a second terminal connected to a second input terminal of the balance terminal amplifier BA1, and a third terminal connected to the output terminal of the ADB circuit.

A first output terminal of the balance terminal amplifier BA1is connected to one terminal of a primary side of the transformer Xfmr7. A second output terminal of the balance terminal amplifier BA1is connected to the other terminal of the primary side of the transformer Xfmr7. A secondary side of the transformer Xfmr7includes one terminal connected to one terminal of a pass-through terminal of the 90-degree differential coupler Q3, and the other terminal connected to the other terminal of the pass-through terminal of the 90-degree differential coupler Q3.

The second balance terminal amplifier module includes balance terminal amplifier BA2, transformer Xfmr5, and transformer Xfmr8. A primary side of the transformer Xfmr5serves as an input terminal of the second balance terminal amplifier module. A secondary side of the transformer Xfmr5includes a first terminal connected to a first input terminal of the balance terminal amplifier BA2, a second terminal connected to a second input terminal of the balance terminal amplifier BA2, and a third terminal connected to the output terminal of the ADB circuit.

A first output terminal of the balance terminal amplifier BA2is connected to one terminal of a primary side of the transformer Xfmr8. A second output terminal of the balance terminal amplifier BA2is connected to the other terminal of the primary side of the transformer Xfmr8. A secondary side of the transformer Xfmr8includes one terminal connected to one terminal of a coupling terminal of the 90-degree differential coupler Q3, and the other terminal connected to the other terminal of the coupling terminal of the 90-degree differential coupler Q3.

The variable XCP includes transistor M1, transistor M2, and transistor M3. A base of the transistor M1is connected to the second output terminal of the driver amplifier DA3, a collector of the transistor M2and the control terminal amplifier module. A base of the transistor M2is connected to the first output terminal of the driver amplifier DA3, a collector of the transistor M1and the control terminal amplifier module. An emitter of the transistor M1is connected to a collector of the transistor M3and an emitter of the transistor M2. An emitter of the transistor M3is grounded. A base of the transistor M3is connected to the output terminal of the ADB circuit.

The control terminal amplifier module includes control terminal amplifier CA, transformer Xfmr6, and transformer Xfmr9. A primary side of the transformer Xfmr6serves as an input terminal of the control terminal amplifier module. A secondary side of the transformer Xfmr6includes one terminal connected to a first input terminal of the control terminal amplifier CA, and the other terminal connected to a second input terminal of the control terminal amplifier CA.

A first output terminal of the control terminal amplifier CA is connected to one terminal of a primary side of the transformer Xfmr9. A second output terminal of the control terminal amplifier CA is connected to the other terminal of the primary side of the transformer Xfmr9. A secondary side of the transformer Xfmr9includes one terminal connected to one terminal of an isolated terminal of the 90-degree differential coupler Q3, and the other terminal connected to the other terminal of the isolated terminal of the 90-degree differential coupler Q1.

As shown inFIG.2, the ADB circuit includes transistor M4nresistor RLP, capacitor CLP, transistor M4n, transistor M5n, transistor M6n, transistor M4p, transistor M5p, transistor M6p, resistor R1, resistor R2, capacitor C1, capacitor C2, capacitor C3and capacitor C4.

The capacitor C1includes one terminal serving as the input terminal of the ADB circuit, and the other terminal connected to one terminal of the resistor R1and a base of the transistor M4.

The other terminal of the resistor R1is connected to a detection voltage. An emitter of the transistor M4is grounded. A collector of the transistor M4is connected to one terminal of the resistor RLP, one terminal of the capacitor CLP, a base of the transistor M4n, a base of the transistor M5n, a base of the transistor M6n, a base of the transistor M4p, a base of the transistor M5p, and a base of the transistor M6p. The other terminal of the resistor RLPis connected to a 1V power supply and the other terminal of the capacitor CLP. A collector of the transistor M4pis connected to a bias voltage V0nti. A collector of the transistor M5pis connected to the bias voltage Vcnt1. A collector of the transistor M6pis connected to a bias voltage Vcnt2. An emitter of the transistor M4pis connected to one terminal of the capacitor C4, one terminal of the resistor R2and a collector of the transistor M4n. The other terminal of the capacitor C4is grounded. An emitter of the transistor M4n is grounded. An emitter of the transistor M5pis connected to one terminal of the capacitor C3, one terminal of the resistor R3and a collector of the transistor M5n.

The other terminal of the capacitor C3is grounded. An emitter of the transistor M5nis grounded. An emitter of the transistor M6pis connected to one terminal of the capacitor C2, one terminal of the resistor R4and a collector of the transistor M6n. The other terminal of the capacitor C2is grounded. An emitter of the transistor M6nis grounded. The other terminal of the resistor R2serves as a first output terminal of the ADB circuit. The other terminal of the resistor R3serves as a second output terminal of the ADB circuit. The other terminal of the resistor R4serves as a third output terminal of the ADB circuit.

As shown inFIG.3, the driver amplifier DA3can be equivalent to a current source Iout, with a parasitic capacitance Cout. The control terminal amplifier CA is equivalent to an input resistor Rinand an input capacitor Cia. The variable XCP is equivalent to a variable resistor.

Rv=Rc(-1gmc)=Rc1-gmc⁢Rc

After the variable XCP is provided between DA3and Xfmr6, a load impedance of the DA3is changed from ZLto ZLv.

ZL→ZLv=RνZL=ZL⁢RcZL-Rc-gmc⁢ZL⁢Rc

The DA3linearly amplifies its input voltage Vin, with a transconductance Gm, thereby obtaining:

V1=Iout×ZLν=Gm⁢Vin⁢ZLvGDA⁢3=V1Vin=Gm⁢ZLv.

As shown inFIGS.4A and4B, the variable XCP structure improves a linearity of the control terminal amplifier CA in a saturation region. The BA1/2using the ADB has a higher gain in the saturation region. With the variable XCP structure, the ADB voltage threshold is high, such that the BA1/2is not turned on in advance to affect an efficiency in the power back-off region.FIG.4Billustrates a solution in which an overall linearity is improved only with an ADB. Due to a large power back-off range, in order to compensate a gain of the CA in saturation and serious compression, the ADB voltage threshold is low to improve the gain of the turn-on BA. Consequently, the BA1/2is turned on in advance to affect the power back-off efficiency.

As shown inFIG.5, the solid line refers to a simulation test result when the variable XCP structure is used in the present disclosure, the dash line refers to a simulation test result when the variable XCP structure is not used under same circuit parameters, and a dotted line refers to a simulation test result when only the ADB is used to improve the linearity. In combination with the variable XCP structure and the ADB (the solid line), the overall linearity of the amplifier is improved. When the variable XCP structure is turned off, and the same ADB voltage threshold is used (the dash line), the linearity of the amplifier is affected, and the power back-off efficiency is reduced slightly. When the variable XCP structure is turned off, and the ADB voltage threshold is improved (the dotted line), the linearity of the amplifier is improved, but the power back-off efficiency is affected seriously. In combination with the variable XCP structure and the ADB, the BA1/2is not turned on in advance for the high ADB voltage threshold to affect the power back-off efficiency.

In an embodiment of the present disclosure, the present disclosure has a higher power back-off efficiency at 28 GHz and 8.5 dB. Compared with the solution only using the ADB, the present disclosure based on the variable XCP structure improves a linearity of the millimeter-wave LMBA, while achieving a higher back-off efficiency. Through the ADB, a direct-current (DC) voltage increasing with an increase of an input signal power is output to control a gate of the transistor M3. With an increase of gme, ZLvincreases. With the increase of the input signal power, Gmdecreases. Through opposite variation tendencies, V1is relatively stable. Therefore, the tendency in which the gain GDA3of the DA3decreases with the increase of the input power is alleviated.

With the variable XCP structure, the present disclosure makes a load impedance of a common-source amplifier increase with a power, thereby preventing a gain of the common-source amplifier from decreasing with the power. The present disclosure improves a linearity of the amplifier, without affecting an efficiency in a power back-off region.