A 1.9 GHz Si-bipolar variable attenuator for PHS transmitter

A 4 dB step 28 dB variable attenuator for 1.9 GHz PHS transmitter was fabricated using silicon bipolar technology. Step accuracy within /spl plusmn/1.2 dB and total vector modulation error of less than 4% are realized for -15 dBm at output. The attenuator consumes 21 mA from 2.7 V power supply and occupies 1.1 mm/spl times/0.5 mm.