High frequency amplifier

Claim 2

A high-frequency amplifier comprising, in combination, a pair of semiconductor elements connected together in a push-pull amplifier circuit configuration, and a pair of capacitors, each connected to one of said semiconductor elements and having a capacitance value at which the capacitor and the output inductance of the semiconductor element to which it is connected together form a resonant circuit which resonates approximately at the frequency of the second harmonic of the signal amplified by said amplifier.

Claim 3

An amplifier as in claim 1 in which said resonant circuit is tuned to resonate at approximately the center frequency of the frequency band for said second harmonic, and means for supplying oscillating energy of a frequency from 30 to 300 megahertz to said amplifier.

Claim 4

An amplifier as in claim 1 in which said semiconductor elements are transistors, each of which has base, emitter and collector electrodes, and each capacitor is connected between the emitter and collector leads of one of said transistors.

Claim 5

An amplifier as in claim 1 including a parallel-plate transmission line forming the connections of said push-pull circuit, the plates of said transmission line also forming said capacitors.

Claim 6

A high-frequency amplifier comprising, in combination, a pair of semiconductor elements connected together in a push-pull circuit configuration by means of a low-impedance transmission line, said transmission line having two sections each of which forms a capacitor connected across one of said semiconductor elements, each capacitor having a capacitance value at which the capacitor and the output inductance of the semiconductor element to which it is connected together form a resonant circuit which resonates approximately at the frequency of the second harmonic of the signal amplified by said amplifier.

Claim 7

A high-frequency amplifier comprising, in combination, a pair of semiconductor elements connected together in a push-pull circuit configuration by means of a low-impedance transmission line, said transmission line having two sections each of which forms a capacitor connected across one of said semiconductor elements, each capacitor having a capacitance value at which the capacitor and the output inductance of the semiconductor element to which it is connected together form a resonant circuit which resonates approximately at the frequency of the second harmonic of the signal amplified by said amplifier.

Claim 8

In a high-frequency amplifier having a plurality of semiconductor devices, each having control electrodes, at least one parallel-plate transmission line connected to a cOntrol electrode of each of a pair of said devices and having a gap in one of its plates, the portions of the plate adjacent the edges of said gap comprising connection terminals.

Claim 9

In a high-frequency amplifier having a plurality of semiconductor devices, each having control electrodes, at least one parallel-plate transmission line connected to a cOntrol electrode of each of a pair of said devices and having a gap in one of its plates, the portions of the plate adjacent the edges of said gap comprising connection terminals.

Claim 10

An amplifier as in claim 6 including another parallel-plate transmission line forming a loop extending between two other electrodes of said devices, said other line also having a gap in one of its plates to form connection terminals.

Claim 11

An amplifier as in claim 7 in which said semiconductor devices consist of two transistors, each having base, emitter and collector electrodes, in which said transmission lines connect the emitter electrodes of said transistors to one another, one of said gaps forming output terminals, and the other of said gaps forming input terminals in said amplifier.

Claim 12

An amplifier as in claim 7 in which said semiconductor devices consist of a pair of transistors, each having base, emitter and collector electrodes, one plate of one of said lines connecting the emitter electrodes of said transistors together, the gap in the other plate of said one line forming terminals for the collector electrodes of said transistors, the gap in the plate of the other line forming terminals for the base electrodes of said transistors.

Claim 13

A high-frequency amplifier comprising, in combination, a pair of semiconductor elements each having base, emitter and collector electrodes and being connected together in a push-pull circuit configuration by means of a low-impedance transmission line, said transmission line having two sections each of which forms a capacitor connected across one of said semiconductor elements, each capacitor having a capacitance value at which the capacitor and the output inductance of the semiconductor element to which it is connected together form a resonant circuit which resonates approximately at the frequency of the second harmonic of the signal amplified by said amplifier, an output transformer comprising a pair of magnetically permeable sleeves, a primary winding and a secondary winding, said windings being aligned with one another side-by-side and wound through said sleeves, said primary winding being connected in series with the emitter-collector paths of said semiconductor elements.

Claim 14

A high-frequency amplifier comprising, in combination, a pair of semiconductor elements each having base, emitter and collector electrodes and being connected together in a push-pull circuit configuration by means of a low-impedance transmission line, said transmission line having two sections each of which forms a capacitor connected across one of said semiconductor elements, each capacitor having a capacitance value at which the capacitor and the output inductance of the semiconductor element to which it is connected together form a resonant circuit which resonates approximately at the frequency of the second harmonic of the signal amplified by said amplifier, an output transformer comprising a pair of magnetically permeable sleeves, a primary winding and a secondary winding, said windings being aligned with one another side-by-side and wound through said sleeves, said primary winding being connected in series with the emitter-collector paths of said semiconductor elements.

Claim 15

An amplifier as in claim 10 including a center-tap for said primary winding, and means for conducting bias current to said center-tap, said transformer comprising a radio-frequency choke as well as a transformer.

Claim 16

An amplifier as in claim 10 in which said primary and secondary windings comprise opposite conductive surfaces of a parallel-plate transmission line.

Claim 17

An amplifier as in claim 12 in which the conductive surface forming one of said windings is divided into two parts of approximately equal length, with one of said sleeves extending around each of said parts, and a center-tap terminal at the midpoint between said parts.

Claim 18

A high-frequency amplifier comprising, in combination, a pair of semiconductor elements, each having base, emitter and collector electrodes and being connected together in a push-pull circuit configuration by means of a low-impedance transmission line, said transmission line having two sections each of which forms a capacitor connected across one of said semiconductor elements, each capacitor having a capacitance value at which the capacitor and the output inductance of the semiconductor element to which it is connected together form a resonant circuit which resonates approximately at the frequency of the second harmonic of the signal amplified by said amplifier, an input transformer comprising a pair of magnetically permeable sleeves, a primary winding and a secondary winding, said windings being aligned with one another side-by-side and wound through said sleeves, one of said windings being connected between the base electrodes of said semiconductor elements.

Claim 19

A high-frequency amplifier comprising, in combination, a pair of semiconductor elements, each having base, emitter and collector electrodes and being connected together in a push-pull circuit configuration by means of a low-impedance transmission line, said transmission line having two sections each of which forms a capacitor connected across one of said semiconductor elements, each capacitor having a capacitance value at which the capacitor and the output inductance of the semiconductor element to which it is connected together form a resonant circuit which resonates approximately at the frequency of the second harmonic of the signal amplified by said amplifier, an input transformer comprising a pair of magnetically permeable sleeves, a primary winding and a secondary winding, said windings being aligned with one another side-by-side and wound through said sleeves, one of said windings being connected between the base electrodes of said semiconductor elements.

Claim 20

An amplifier as in claim 14 including a center-tap for said one winding, an R-F choke connected to said center-tap and providing a return path for direct bias Current to said base electrodes, and impedance means connected across said choke.

Claim 21

An amplifier as in claim 14 in which said windings are aligned coaxially, with one of said windings comprising a conductive sleeve around the other winding, with insulation between said windings.

Claim 22

A high-frequency amplifier comprising, in combination, a pair of semiconductor elements, each having base, emitter and collector electrodes and being connected together in a push-pull circuit configuration by means of a low-impedance transmission line, said transmission line having two sections each of which forms a capacitor connected across one of said semiconductor elements, each capacitor having a capacitance value at which the capacitor and the output inductance of the semiconductor element to which it is connected together form a resonant circuit which resonates approximately at the frequency of the second harmonic of the signal amplified by said amplifier, an input transformer comprising a pair of magnetically permeable sleeves, a primary winding and a secondary winding, said windings being aligned with one another side-by-side and wound through said sleeves, one of said windings being connected between the base electrodes of said semiconductor elements, an output transformer comprising a pair of magnetically permeable sleeves, a primary winding and a secondary winding, said windings being aligned with one another side-by-side and wound through said sleeves, said primary winding being connected in series with the emitter-collector paths of said semiconductor elements.

Claim 23

A high-frequency amplifier comprising, in combination, a pair of semiconductor elements, each having base, emitter and collector electrodes and being connected together in a push-pull circuit configuration by means of a low-impedance transmission line, said transmission line having two sections each of which forms a capacitor connected across one of said semiconductor elements, each capacitor having a capacitance value at which the capacitor and the output inductance of the semiconductor element to which it is connected together form a resonant circuit which resonates approximately at the frequency of the second harmonic of the signal amplified by said amplifier, an input transformer comprising a pair of magnetically permeable sleeves, a primary winding and a secondary winding, said windings being aligned with one another side-by-side and wound through said sleeves, one of said windings being connected between the base electrodes of said semiconductor elements, an output transformer comprising a pair of magnetically permeable sleeves, a primary winding and a secondary winding, said windings being aligned with one another side-by-side and wound through said sleeves, said primary winding being connected in series with the emitter-collector paths of said semiconductor elements.

Claim 24

An amplifier as in claim 17 in which transmission line is a parallel-plate transmission line which is bent into a loop to form closely adjacent output terminals for the interconnected semiconductor elements.