A very compact wideband HBT MMIC VCO, with two output buffers, require
d for L band mobile telecommunciations, such as DCS1800, has been fabr
icated and tested. The VCO has a large bandwidth of 400MHz with an out
put power between -1.4 and 2.3dBm, it exhibits a -80dBc/Hz phase noise
at 100kHz off the carrier at 1.75GHz and a frequency pull of less tha
n 10MHz. The circuit area is as small as 1.2 x 1.2mm2.