Abstract: The present invention relates to a process and a system for reducing leakage of LO to the RF-port (LLO) in a real system that converts the frequency of a first signal, i.e. the LO signal, by mixing the first signal with a second supplied signal SI to a third signal SO of a frequency that is different from the frequency of the first and second signal. More specifically the invention relates to a process and a system that are applied to suppress LLO in real image reject balanced passive mode transistor mixers. Further, the invention also relates to a balanced passive mode transistor mixer and an image reject balanced mixer to be used in said process and system.

Abstract: There is described a system and a process for reducing leakage of LO (LLO) in a system which converts the frequency of a first signal by mixing the first signal with a second supplied signal to a third signal having a frequency which is different from the frequency for the first and second signal, where the first signal is divided via a number of couplers into four part-signals which are phase-shifted relative to each other, and that each such part-signal is led through its respective transistor there being added via each transistor a second signal which is mixed with the first signal, and that the signals which pass through the transistors are modulated by a number of regulating means for each transistor, preferably one or two per transistor, and that the frequency-shifted part-signals are added to a third signal via a number of couplings after having been phase-shifted, the voltage regulators being adjustable so that the signals are modulated and LLO is reduced.