IMPROVED LOCAL OSCILLATOR (LO) DRIVER CIRCUIT FOR A MIXER

摘要

An improved local oscillator (LO) driver circuit for a mixer, the LO driver circuit includes a gain circuit responsive to LO input signals at a predetermined LO frequency range. At least a first pair of a parallel combination of a resistor and a capacitor is coupled to the gain circuit and to LO inputs of the mixer. The resistor configured to increase impedance at low frequencies of the frequency range and the capacitor is configured to reduce the impedance of the first parallel combination at high frequencies of the frequency range to reduce resistive impendence of the resistor. At least a second pair of a parallel combination of a low quality factor inductor and a high quality factor inductor is connected to the first pair. The second pair in serial combination with the first pair is tuned to provide a constant desired load impedance and a constant desired voltage swing at the LO inputs of the mixer over the predetermined LO frequency range.