Transformer-based Marchand Balun amplifier for wireless communication

A radio frequency (RF) transceiver comprising an intermediate amplifier to amplify a differential signal, the intermediate amplifier comprising:

• a first and a second differential input ports, and a single-ended output port;
• a first transistor with a first gate, first source, and first drain terminals, wherein the first source terminal is coupled to a reference plane and the first gate terminal is coupled to the first differential input port;
• a second transistor with a second gate, second source, and second drain terminals, wherein the second source terminal is coupled to the reference plane and the second gate terminal is coupled to the second differential input port;
• and
• a Balun co-designed with the amplifier, the Balun comprising:
• a primary transformer winding having one end coupled to the first drain terminal of the first transistor, an opposite end coupled to the second drain terminal of the second transistor, and a center tap coupled to a bias voltage;
• and
• a secondary transformer winding adjacent to the primary transformer winding and having one end coupled to the single-ended output port and an opposite end open circuited, wherein an electromagnetic field generated at the primary transformer winding induces a signal at the secondary transformer winding, wherein the primary transformer winding of the Balun co-designed with the amplifier serves as a matching transformer for the first and second transistors of the amplifier, wherein an operating frequency bandwidth of the amplifier is approximately 3.45 Gigahertz (GHz) to 19.05 GHz.

A radio frequency (RF) frontend comprising:

• one or more RF transceivers, each RF transceiver having an intermediate amplifier to amplify a differential signal, the intermediate amplifier comprising:
• a first and a second differential input ports, and a single-ended output port;
• a first transistor with a first gate, first source, and first drain terminals, wherein the first source terminal is coupled to a reference plane and the first gate terminal is coupled to the first differential input port;
• a second transistor with a second gate, second source, and second drain terminals, wherein the second source terminal is coupled to the reference plane and the second gate terminal is coupled to the second differential input port;
• and
• a Balun co-designed with the amplifier, the Balun comprising:
• a primary transformer winding having one end coupled to the first drain terminal of the first transistor, an opposite end coupled to the second drain terminal of the second transistor, and a center tap coupled to a bias voltage;
• and
• a secondary transformer winding adjacent to the primary transformer winding and having one end coupled to the single-ended output port and an opposite end open circuited, wherein an electromagnetic field generated at the primary transformer winding induces a signal at the secondary transformer winding, wherein the primary transformer winding of the Balun co-designed with the amplifier serves as a matching transformer for the first and second transistors of the amplifier, wherein an operating frequency bandwidth of the amplifier is approximately 3.45 Gigahertz (GHz) to 19.05 GHz.