Complementary tuned mixer

摘要

A mixer circuit for frequency conversion operates with low power supply voltage lower than 1 V. The circuit comprises a first pair (1) of N-channel MOS transistors and a second pair (2) of N-channel MOS transistors each receiving differential local frequency signal (LO(+), LO(-)), and a third pair (3) of P-channel MOS transistors receiving differential radio frequency signal (RF(+), RF(-)). Each of pair (1, 2, 3) of transistors is coupled in series with a parallel resonance circuit (4, 5, 6) which operates as a constant current source. A drain of each transistors (MP1, MP2) of the third pair (3) of transistors is connected to a junction of a first pair (1) and a second pair (2) of transistors and a parallel resonance circuit (4, 5). An output intermediate frequency signal (IF(+), IF(-)) which is difference between the local frequency and the radio frequency is obtained at the junction of drains of the first (1) and the second (2) pair of transistors and load resistors (RL1, RL2). No series connected transistor is inserted between a power source (VDD) and a ground, and each pairs (1, 2, 3) of transistors are inserted between the power source (VDD) and the ground essentially in parallel with one another.