| 摘要 |
An AM converter and AGC amplifier are described for use either separately or in combination in a radio receiver. The AGC amplifier includes a semiconductor device directly coupled to the amplifier input for receiving automatic gain control signals. The AM converter includes a single mixer transistor directly coupled to both an RF amplifier and local oscillator. The converter circuit provides attenuation of the oscillator signal by up to 60 d.b. relative to the R.F. signal, greatly reducing the necessary I.F. filtering. Both the converter and AGC circuits are fabricated on integrated circuit chips.
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