Two dimensional integrated power combiner for rf power amplifiers

Abstract

A novel and useful radio frequency (RF) front end module (FEM) circuit that provides high linearity and power efficiency and meets the requirements of modern wireless communication standards such as 802.11 WLAN, 3G and 4G cellular standards, Bluetooth, ZigBee, etc. The configuration of the FEM circuit permits the use of common, relatively low cost semiconductor fabrication techniques such as standard CMOS processes. The FEM circuit includes a power amplifier made up of one or more sub-amplifiers having high and low power circuits and whose outputs are combined to yield the total desired power gain. An integrated multi-tap transformer having primary and secondary windings arranged in a novel configuration provide efficient power combining and transfer to the antenna of the power generated by the individual sub-amplifiers.

What is claimed is: 
     
         1 . An integrated circuit transformer, comprising:
 a semiconductor substrate for supporting a plurality of layers of an integrated circuit;   a plurality of substantially rectangular shaped primary windings configured in a 2D grid pattern wherein each primary winding is adjacent to two other primary windings; and   a substantially rectangular shaped secondary winding routed around each primary winding in figure eight fashion so as to maximize power coupling and impedance transformation from said primary windings to said secondary winding.   
     
     
         2 . The integrated circuit transformer according to  claim 1 , wherein each primary winding is coupled to the output of a radio frequency (RF) power amplifier. 
     
     
         3 . The integrated circuit transformer according to  claim 1 , wherein the number of primary windings is four. 
     
     
         4 . The integrated circuit transformer according to  claim 1 , wherein the input impedance of said transformer is configured to substantially match the output impedance of a preceding power amplifier stage. 
     
     
         5 . The integrated circuit transformer according to  claim 1 , wherein the inductance of each primary winding of said transformer is configured such that its impedance substantially matches the output impedance of a preceding power amplifier stage. 
     
     
         6 . The integrated circuit transformer according to  claim 1 , wherein said transformer is operative to combine the output power of four power amplifiers into a single output load. 
     
     
         7 . The integrated circuit transformer according to  claim 1 , wherein said transformer is fabricated using a semiconductor technology selected from the group consisting of complementary metal oxide semiconductor (CMOS), Gallium Arsenide (GaAs), Silicon Germanium (SiGe), Indium Gallium Phosphide (InGaP) and Gallium Nitride (GaN). 
     
     
         8 . The integrated circuit transformer according to  claim 1 , wherein said transformer is adapted to transmit signals conforming to a wireless standard selected from the group consisting of 802.11 WLAN, LTE, WiMAX, HDTV, 3G cellular, 4G cellular and DECT. 
     
     
         9 . An integrated circuit transformer, comprising:
 a semiconductor substrate for supporting a plurality of layers of an integrated circuit;   a plurality of substantially octagon shaped outer primary windings configured in a 2D grid pattern wherein each outer primary winding is adjacent two other outer primary windings;   a plurality of substantially octagon shaped inner primary windings configured in a 2D grid pattern wherein each inner primary winding is routed inside its respective outer primary winding, wherein each outer and inner primary winding are electrically coupled at their respective input terminals;   a plurality of center taps, each center tap electrically coupled to its respective outer and inner primary windings; and   a substantially octagon shaped secondary winding routed between each outer primary winding and inner primary winding and electrically coupled in the center of said grid, said routing adapted to maximize power coupling and impedance transformation from said outer and inner primary windings to said secondary winding.   
     
     
         10 . The integrated circuit transformer according to  claim 9 , wherein each outer and inner primary winding is coupled to the output of a radio frequency (RF) power amplifier. 
     
     
         11 . The integrated circuit transformer according to  claim 9 , wherein the number of outer primary windings is four and the number of inner primary windings is four. 
     
     
         12 . The integrated circuit transformer according to  claim 9 , wherein the input impedance of said transformer is configured to substantially match the output impedance of a preceding power amplifier stage. 
     
     
         13 . The integrated circuit transformer according to  claim 9 , wherein the inductance of each outer and inner primary winding of said transformer is configured such that its impedance substantially matches the output impedance of a preceding power amplifier stage. 
     
     
         14 . The integrated circuit transformer according to  claim 9 , wherein said transformer is operative to combine the output power of four power amplifiers into a single output load. 
     
     
         15 . The integrated circuit transformer according to  claim 9 , wherein said transformer is fabricated using a semiconductor technology selected from the group consisting of complementary metal oxide semiconductor (CMOS), Gallium Arsenide (GaAs), Silicon Germanium (SiGe), Indium Gallium Phosphide (InGaP) and Gallium Nitride (GaN). 
     
     
         16 . The integrated circuit transformer according to  claim 9 , wherein said transformer is adapted to transmit signals conforming to a wireless standard selected from the group consisting of 802.11 WLAN, LTE, WiMAX, HDTV, 3G cellular, 4G cellular and DECT.