| 摘要 |
PURPOSE:To suppress the transmission at spurious band by providing a sub- resonance resonator having a low Q near a main resonance line. CONSTITUTION:An input Pi is transmitted to an output line 33 via the main resonance line 32 coupled to a line 31. A BPF is constituted by connecting two stages of the main resonance lines 32 in series. The sub-resonance line 34 resonated at a spurious band frequency of the BPF is provided by being coupled with the main resonance line 32. The sub-resonance line 34 is formed by a thin film made of Ni, Cr or TaN2. Thus, the Q is low and the line is resonated with the harmonic spurious frequency so as to absorb the spurious components. The device operation stable always is realized by using the filter for a circuit such as oscillator, multiplier or power amplifier where the spurious radiation is a problem. |
