Hyperabrupt Junction Varactor Diodes Eye Low Noise VCO Apps

Boasting of a high capacitance ratio (C_TR ) and low series resistance (R_S), the SMV1763-079 and SMV1770-079 silicon hyperabrupt junction varactor diodes are said to be particularly well-suited for use in low phase noise voltage-controlled oscillators (VCOs) employed in wireless systems operating at frequencies up to and beyond 2.5 GHz. Specifically, the tuning varactors are targeted at high-volume, low-cost battery-powered applications, such as in low-noise and wideband UHF and VHF VCOs for GSM, PCS, CDMA and analog phones.
Besides a high C_TR and low R_S, the SMV1763-079 and SMV1770-079 tuning varactors also offer a forward current of 20 mA (max.), power dissipation of 250 mW (max.), and an operating temperature range of -55°C to 125°C. Breakdown voltage for the devices at I_R = 10 µA is 10V and 12V (min.), respectively. The hyperabrupt junction varactor diodes come in the ultra-small SC-79 package and cost $0.21 each/100K.