A Low Noise Ku-Band SiGe Phase Locked Oscillator

A fully integrated 13.3-15.3 GHz phase locked oscillator (PLO) has been developed using an 80 GHz
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SiGe HBT technology. The PLO consists of a push-push VCO, buffers, frequency doubler, 32/64 dual modulus prescaler, a phase frequency detector (PFD) with lock detect, and an operational amplifier. The output power at 15 GHz is 7dBm. The VCO has a respectable phase noise of -96 dBc/Hz at 100KHz offset. The prescaler has an excellent phase noise floor of-162 dBc/Hz at 113 MHz. The noise floor of the PLO is -104 dBc/Hz at 1KHz offset and -110 dBc/Hz at 1MHz offset at a reference frequency of 113 MHz. The PLO has very linear, nearly flat, tuning sensitivity of 650-750 MHz/V across the band.