| 摘要 |
<p>The circuit improves frequency stability, and extends a variable frequency range by a negative feedback and negative resistance circuit. The circuit includes a 1st condenser (C1) and negative resistance circuit, a 2nd condenser (C2) which connects a 2nd gm amplifier output terminal to ground. The negative resistance circuit (12) between 1st gm amplifier (10) and 2nd gm amplifier (11), improves frequency stability, adjusts a selectivity, and specifies oscillating conditions. The gm amplifier varies a gm value by voltage control signal (Vctl), and varies an oscillating frequency, and specifies an oscillating frequency.</p> |
