Transmitter architectures [GSM handsets]

Transmitter circuits in today´s mobile telephone handsets provide good RF performance at high efficiencies and in a compact implementation. Circuit trends over the past few years have pushed manufacturing and component technology to a point where a typical GSM transmitter can be fitted into the size of a 2-pence piece. TDMA communications systems like GSM, PDC and IS-54 also need good immunity against power amplifier keying and better control of power ramping profiles to minimise transmitted interference. Other digital standards like CDMA also require a high degree of linearity on both the receiver and transmitter. The author discusses digital transmitter circuit trends, GSM/TDMA architectures, CDMA techniques, linearisation techniques, and dual-band architectures