Low cost voltage controlled oscillators for X-band mobile communication purposes realized with Si HBTs and SiGe HBTs

Design and test results of X-band low cost VCOs using silicon bipolar transistors (Siemens SIEGET T502A) and silicon-germanium HBTs (Vishay-Telefunken) as active devices are presented. The oscillators are realized on a 5 mil alumina substrate and can be operated between 9.4 GHz and 9.8 GHz. The employed varactor diode is a commercially available silicon chip (MACOM 45225-132). Measured phase noise data better than -89 dBe @ 100 kHz and -110 dBc @ 1 MHz demonstrate the suitability of these sources for key components in mobile communication systems.