Impedance-matched, class F high-frequency amplifier
First Claim
1. A high frequency amplifier for amplifying an input high frequency signal which has a fundamental frequency, comprising:
- an active device which amplifies in power the fundamental frequency of the input high frequency signal; and
an output circuit which is coupled between an output terminal of the active device and an output transmission line, the output circuit including an output matching circuit which matches an output from said active device with said output transmission line for the fundamental frequency and also for a second harmonic frequency thereof, and an even harmonic terminating circuit, connected to an output side of the output matching circuit, which has a high input impedance at the fundamental frequency and a low input impedance at least at the second harmonic frequency thereof.
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Accused Products
Abstract
An impedance matched class-F high frequency amplifier includes an input matching circuit receiving high frequency signals connected to the gate of the FET. The drain of the FET is connected to an output matching circuit which matches the fundamental frequency and the second harmonic frequency, and the output of the output matching circuit is connected to an even harmonic terminating circuit. The stray reactance componance at the output impedance of the FET is offset by the output matching circuit, and therefore the even harmonics terminating circuit can more accurately terminate the second harmonic frequencies.
139 Citations
20 Claims
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1. A high frequency amplifier for amplifying an input high frequency signal which has a fundamental frequency, comprising:
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an active device which amplifies in power the fundamental frequency of the input high frequency signal; and an output circuit which is coupled between an output terminal of the active device and an output transmission line, the output circuit including an output matching circuit which matches an output from said active device with said output transmission line for the fundamental frequency and also for a second harmonic frequency thereof, and an even harmonic terminating circuit, connected to an output side of the output matching circuit, which has a high input impedance at the fundamental frequency and a low input impedance at least at the second harmonic frequency thereof. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. An impedance matched high frequency amplifier, comprising:
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means for receiving an input high frequency signal which has a fundamental frequency and at least one harmonic frequency of the fundamental frequency; an amplifying structure, receiving said input high frequency signal and producing an amplified output thereof; a first output matching circuit, having matching components which match an output impedance of said amplifier with an impedance of an output transmission line for at least the fundamental frequency and a second harmonic frequency, said output matching circuit receiving the amplified output of said amplifier as an input, and producing a first matched output; and a harmonic terminating circuit, connected to said first matched output, which has a high impedance to ground at the fundamental frequency, and a low impedance to ground at the second harmonic frequency, said harmonic terminating circuit operating independent of stray reactance in the amplifier due to said matching by said first output matching circuit, since the output impedance of the amplifier is offset by the first output matching circuit, so that the real reactance to be connected to the amplifier becomes the harmonic terminating circuit. - View Dependent Claims (9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20)
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Specification