Broadband balun and impedance transformer for push-pull amplifiers

Claim 2

A balun and impedance transformer for a power amplifier, comprising: a first 4:1 impedance transformer having a differential input port and a differential output port the differential input port coupled to the power amplifier; a balun configured in a Marchand configuration, the balun having a differential input port with a coupling capacitor coupled therebetween and the balun having a single-ended output port, the balun's differential input port coupled to the differential output port of the first 4:1 impedance transformer; a second 4:1 impedances transformer having a single-ended input port capacitively coupled to the balun's single-ended output port, the second 4:1 impedance transformer having a single-ended output port; and the first 4:1 impedance transformer, the balun and the second 4:1 impedance transformer are implemented using Low Temperature Cofired Ceramics (LTCC) technology, wherein the first 4:1 impedance transformer and the balun provide DC bias to the power amplifier and further comprising a decoupling capacitor on the DC bias to serve as a floating ground place.

Claim 3

The balun and impedance transformer of claim 1 , wherein the balun and impedance transformer provides a 16:1 impedance conversion.

Claim 4

A balun/impedance transformer, comprising: a 4:1 impedance transformer comprising: a first transmission line coupler formed of first and second adjacent transmission lines, the transmission line having first and second opposed terminals and the second transmission line having third and fourth opposed terminals, the first and fourth terminals being diagonally opposed, the first terminal being DC biased, the second terminal being an input port, the third terminal being shorted to the second terminal, and the fourth terminal providing a first output port; a second transmission line coupler formed of third and fourth adjacent transmission lines, the third transmission line having first and second opposed terminals, the fourth transmission line having third and fourth opposed terminals, the first terminal of the third transmission providing a second input port, the second terminal of the third transmission being DC biased, the third terminal of the fourth transmission line providing a second output port, and the fourth terminal of the fourth transmission line being short circuited to the second input port; a balun formed of: a first transmission line coupler formed of first and second adjacent transmission lines, the first transmission line having first and second opposed terminals and the second transmission line having third and fourth opposed terminals; a second transmission line coupler formed of third and fourth adjacent transmission lines, the third transmission line having first and second opposed terminals, the fourth transmission line having third and fourth opposed terminals; wherein the balun's first terminal of the first coupler and the second terminal of the second coupler am DC biased, the second terminal of the first coupler and the first terminal of the second coupler arm capacitively coupled through a capacitor and provide first and second input ports, the fourth terminal of the first coupler and the third terminal of the second coupler are shorted together, the fourth terminal of the second coupler being open circuited, and the third terminal of the first coupler providing a single-ended output port; a second 4:1 impedance transformer formed of first and second adjacent transmission lines, the first transmission line formed of first and second opposed terminals, the second transmission line formed of third and fourth opposed terminals, the first and fourth terminals being diagonally opposed and capacitively coupled to the balun output port the second terminal being grounded, the third terminal providing an output port; wherein the first and second input ports of the first 4:1 transformer provide two balance differential ports for a push-pull amplifer.

Claim 5

A balun/impedance transformer, comprising: a 4:1 impedance transformer comprising: a first transmission line coupler formed of first and second adjacent transmission lines, the transmission line having first and second opposed terminals and the second transmission line having third and fourth opposed terminals, the first and fourth terminals being diagonally opposed, the first terminal being DC biased, the second terminal being an input port, the third terminal being shorted to the second terminal, and the fourth terminal providing a first output port; a second transmission line coupler formed of third and fourth adjacent transmission lines, the third transmission line having first and second opposed terminals, the fourth transmission line having third and fourth opposed terminals, the first terminal of the third transmission providing a second input port, the second terminal of the third transmission being DC biased, the third terminal of the fourth transmission line providing a second output port, and the fourth terminal of the fourth transmission line being short circuited to the second input port; a balun formed of: a first transmission line coupler formed of first and second adjacent transmission lines, the first transmission line having first and second opposed terminals and the second transmission line having third and fourth opposed terminals; a second transmission line coupler formed of third and fourth adjacent transmission lines, the third transmission line having first and second opposed terminals, the fourth transmission line having third and fourth opposed terminals; wherein the balun's first terminal of the first coupler and the second terminal of the second coupler am DC biased, the second terminal of the first coupler and the first terminal of the second coupler arm capacitively coupled through a capacitor and provide first and second input ports, the fourth terminal of the first coupler and the third terminal of the second coupler are shorted together, the fourth terminal of the second coupler being open circuited, and the third terminal of the first coupler providing a single-ended output port; a second 4:1 impedance transformer formed of first and second adjacent transmission lines, the first transmission line formed of first and second opposed terminals, the second transmission line formed of third and fourth opposed terminals, the first and fourth terminals being diagonally opposed and capacitively coupled to the balun output port the second terminal being grounded, the third terminal providing an output port; wherein the first and second input ports of the first 4:1 transformer provide two balance differential ports for a push-pull amplifer.

Claim 6

The balun/impedance transformer of claim 3 , wherein the balun transformer provides a broadband impedance of 16:1.

Claim 7

The balun/impedance transformer of claim 3 , wherein the output port is characterized by an impedance of substantially 50 ohms and the first and second input ports are each characterized by a low impedance of approximately 3 to 4 ohms.

Claim 8

The balun and impedance transformer of claim 3 , wherein the balun and impedance transformer are implemented using Low Temperature Cofired Ceramics (LTCC) technology.

Claim 9

The balun and impedance transformer of claim 3 , wherein the balun and impedance transformer are implemented using High Density Interconnect (HDI) technology.

Claim 10

A balun and impedance transformer for a push-pull amplified, comprising: a first 4.1 impedance transformer for receiving a differential input and generating a differential output; a second 4:1 impedance transformer, a balun cascaded between the first and second 4:1 impedance transformers, the balun having a differential input port and a single-ended output port; a coupling capacitor across the balun differential input port; DC bias applied to the first 4:1 transformer and the balun; a decoupling capacitor coupled to the DC bias to provide a floating ground plant with the push-pull amplifier; and the balun and first and second 4:1 impedance transformers arm implemented using Low Temperature Cofired Ceramics (LTCC) technology.

Claim 11

A balun and impedance transformer for a push-pull amplified, comprising: a first 4.1 impedance transformer for receiving a differential input and generating a differential output; a second 4:1 impedance transformer, a balun cascaded between the first and second 4:1 impedance transformers, the balun having a differential input port and a single-ended output port; a coupling capacitor across the balun differential input port; DC bias applied to the first 4:1 transformer and the balun; a decoupling capacitor coupled to the DC bias to provide a floating ground plant with the push-pull amplifier; and the balun and first and second 4:1 impedance transformers arm implemented using Low Temperature Cofired Ceramics (LTCC) technology.

Claim 12

The balun and impedance transformers of claim 8 , wherein the balun and first and second 4:1 impedance transformers are implemented using High Density Interconnect (HDI) technology.