MEMS-based adaptive impedance matching network
Ashok Srivastava · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 2003
The architecture level design of an impedance matching network is presented for the global system for mobile communication radio frequency (GSM RF) power amplifier module used in a typical cellular handset. Designs for the low and high output impedance of the power amplifier and 50 Ω antenna impedance are considered. Impedance matching network design is presented for a typical low output impedance (Z = 2-j*0.4 Ω) of the power amplifier and 50 Ω antenna impedance and is made adaptive for high output impedance (Z = 7+j*2 Ω). It is shown that the network can be made adaptive to varying output requirements of the power amplifier by tuning the network capacitance toward the antenna end. The architecture level design of a 25 Ω antenna impedance is also presented and shown that that the impedance matching network can be made adaptive, which would require the use of MEMS switches. The adaptive impedance matching networks can be implemented in a passive integration technology with post-processing for MEMS components.