| 摘要 |
PURPOSE:To obtain a variable phase shifter which can be integrated and miniaturized by varying the gain of a variable gain amplifier which amplifies each output signal of a surface acoustic wave element and then varying the phase of the output of a synthesizing element which synthesizes the output of the variable gain amplifier. CONSTITUTION:For a surface acoustic wave element 1, the surface acoustic wave excited by an input electrode 1a is converted into an electric signal by output electrodes 1b and 1c. These electrodes 1b and 1c produce different output phases. The output of the electrode 1b is amplified by a variable gain amplifier 2; while the output of the electrode 1c is amplified by a variable gain amplifier 1c. These amplified outputs are applied to input electrodes 7a and 7b of a surface acoustic wave element 7, and this element 7 functions as a synthesizing element. The gains of amplifiers 2 and 3 are varied to change the output phase shift generated from the electrode 7b of the element 7. Both elements 1 and 7 can be formed on the same surface acoustic wave substrate U and also converted into an IC. Thus, a compact and light-weight variable phase shifter is obtained. |
