| 摘要 |
FIELD: communications engineering. ^ SUBSTANCE: proposed device has sections 1 identical in structure and built around operational amplifier 3 with negative feedback circuits 4, 5 and with piezoelectric resonator 6. Outputs of sections are connected to respective inputs of adder 2 built around operational amplifier 8 and resonators 9 - 12. Each operational amplifier 3 has output-stage current control lead connected to outputs of control unit 14. Operational amplifiers 3 whereto control current is not supplied from output stage are at high-impedance state in which they do not influence operation of other sections thereby affording high degree of channel-to-channel isolation. ^ EFFECT: simplified design of digital central frequency tunable filter. ^ 1 cl, 3 dwg |
