PURPOSE: To prevent a local oscillation signal from being leaked to an RF signal terminal by providing a local oscillation signal interruption circuit between a microstrip line/slot line conversion section and the 1st microstrip line/ coplaner line conversion section and providing a diode between the local oscillation signal terminal and an IF signal terminal.
CONSTITUTION: A local oscillation signal inputted to local oscillation signal terminals T3, T4 is given to the 1st microstrip line/coplaner line conversion section 7, where the signal is distributed into the 2nd and 3rd coplaner lines 15, 16. The local oscillation signal distributed in the coplaner line 15 is reflected nearly completely at the local oscillation signal interruption circuit 14 and the local oscillation signal is sent to the coplaner line 16. Then part of the local oscillation signal passing through the circuit 14 is propagated through the 1st and 2nd slot lines 3, 4, and in making the electric length of the slot lines 3, 4 equal to each other, since the signal is inputted inversely at a reference face S4 of the microstrip line/slot line conversion section 2, the local oscillation signal is not leaked to the RF siganl terminals T1, T2.
NAGASE KATSUTERU
IMATANI TOSHIO
MITSUBISHI ELECTRIC CORP