Integrated circuit oscillator and radiotelephone using such an oscillator

摘要

The oscillator (OSC) generates a variable frequency output signal (LO) delivered at two terminals (S1,S2). The output signal is controlled by a tuning signal (Vtun) applied to the oscillator input terminal. Two Schottky diodes are connected as capacitors between the output terminals. A resistor R connects the node between the two diodes to the oscillator input. Two bipolar transistors (T1,T2) form the active part of the oscillator. The transistor emitters are connected to a current source (REE). Two high-pass filters are connected between the output terminals and variable capacitors (Cs).