| 摘要 |
PURPOSE:To simplify the constitution of a mixer circuit and to improve the characteristic of said circuit by using an FET for microwave as a mixer element, and applying the reception signal and the local oscillation signal to the gate and the source respectively to deliver an IF signal through the drain. CONSTITUTION:An FET30 is used as a mixer elment of a microwave mixer circuit, and a high frequency reception signal RF is supplied to the gate of the FET30 via an input matching circuit 29. At the same time, the local oscillation signal L0 supplied from a matching circuit for local oscillation signal is applied to the source of the FET30. A tip open line 34 having 1/4lambda electrical length in terms of the signal RF frequency band is connected to the source of the FET30 together with a tip short-circuit line 35 having 1/4lambda electrical length in terms of the signal L0 frequency band. In addition, an LPF32 is connected to the drain of the FET30 via a high frequency trap circuit 31. Thus the circuit constitution is simplified, and the IF signal is delivered through an intermediate signal output terminal 33. The separation performance is improved between signals RF and L0.
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