Peaking amplifier frequency tuning

A peaking amplifier circuit, comprising:

• an input node, an output node, a first feedback node, and a second feedback node;
• a first input amplifier having an input connected to the input node and an output connected to the first feedback node;
• a second input amplifier having an input connected to the input node and an output connected to the second feedback node;
• a coupling capacitor connected between the first feedback node and the second feedback node;
• an amplifier having an input connected to the first feedback node and an output connected to the output node;
• a base feedback amplifier in a negative feedback loop with an input connected to the output node and an output connected to the first feedback node;
• a capacitor and a load impedance in series connected from the first feedback node to a source voltage;
• a first tunable feedback amplifier in a negative feedback loop with an input connected to the output node and an output connected to the second feedback node;
• a second tunable feedback amplifier in a positive feedback loop with an input connected to the output node and an output connected to the second feedback node;
• and
• a tuning circuit for applying a first tuning voltage to the first tunable feedback amplifier and for applying a second tuning voltage to the second tunable feedback amplifier.

A peaking amplifier circuit, comprising:

• a first input amplifier having an input connected to an input node and an output connected to a first feedback node;
• a second input amplifier having an input connected to the input node and an output connected to a second feedback node;
• a coupling capacitor connected between the first feedback node and the second feedback node;
• an amplifier with an input connected to the first feedback node and an output connected to an output node;
• an untuned feedback amplifier with an input connected to the output node and an output connected to the first feedback node;
• a first tunable feedback amplifier with an input connected to the output node and an output connected to the second feedback node;
• a second tunable feedback amplifier with an input connected to the output node and an output connected to the second feedback node;
• and
• a tuning circuit for selectively applying a first tuning voltage to the first tunable feedback amplifier and a second tuning voltage to the second tunable feedback amplifier.