射頻發射器(I)

A 5.8 GHz transmitter front-end comprising a
quadrature modulator, a variable gain amplifier
and an on-chip output balun in CMOS 0.18-um
technology is presented. The quadrature
modulator adopts cross-coupled type
micro-mixer, and the measured 3rd-oder
rejection is 32 dB under input voltage swing of
250 mVpp. With four-bit control words, a
16-step linear-in-dB output power is realized to
achieve a dynamic range of 27 dB. A
single-ended type output is accomplished by an
on-chip 3:1 transformer and the output
matching network is therefore simplified.