Monolithic integrated circuit device including AC negative feedback type high frequency amplifier circuit

Claim 2

A monolithic integrated circuit device including an AC negative feedback type high frequency amplifier circuit characterised by: a substrate (10) on which said monolithic integrated circuit device is formed; and an AC negative feedback circuit (14) for said high frequency amplifier circuit (12) including a semi-conductor impedance element (41) connected to an external terminal (lld) on said substrate, which is connected to a variable control means (20) for adjusting an amount of AC feedback of said high frequency amplifier circuit.

Claim 3

A monolithic integrated circuit device according to claim 1 characterised in that said semiconductor impedance element (41) comprises a junction capacitance of a diode (41) supplied with a reverse bias voltage.

Claim 4

A monolithic integrated circuit device according to claim 1 characterised in that said high frequency amplifier circuit (12) comprises a transistor (31) with its base electrode supplied with an input signal (lla), a load resistor (32) connected between a first source of reference voltage (+V) and a collector electrode of said transistor, a DC negative feedback resistor (33) connected between a second source (llc) of reference voltage and an emitter electrode of said transistor, and a diode (41) constituting said AC negative feedback circuit, one end of said diode (41) being connected to the emitter electrode of said transistor (31) and the other and of said diode being connected to said variable control means (20) through said external terminal (lld).

Claim 5

A monolithic integrated circuit device according to claim 1 characterised in that said high frequency amplifier circuit comprises: two sets of serially connected members, each including a load resistor (32A,32B), a transistor (31A,31B) and a DC negative feedback resistor (33A,33B); a current source (35) commonly connected to first ends of the respective DC negative feedback resistors; and two diodes (41A,41B) with first ends being connected to respective emitter electrodes of said transistors, the other ends of the diodes being commonly connected to said variable control means (20) through said external terminal (lId).

Claim 6

A monolithic integrated circuit device according to any one of claims 2 to 4 characterised in that the or each said diode (41,41A,41B) is connected to said high frequency amplifier circuit (12) via a capacitor (42,42A,42B) for blocking direct current.

Claim 7

A monolithic integrated circuit device according to claim 5 characterised by a resistor (43,43A, 43B) connected between a juncture between the or each said diode and said capacitor and said external terminal (lld).

Claim 8

A monolithic integrated circuit device according to claim 1 characterised in that said semiconductor impedance element comprises a diffusion capacitance between base and emitter electrodes of a transistor (51).

Claim 9

A monolithic integrated circuit device according to claim 1 characterised in that said semiconductor impedance element comprises a diffusion capacitance between base and collector electrodes of a transistor (51).

Claim 10

A monolithic integrated circuit device according to claim 7 or claim 8 characterised in that said AC negative feedback circuit (14) comprises: first and second said transistors (51,52) each having a plurality of output electrodes and a base electrode; and a variable current source (53); first output electrodes, of said first and second transistors are commonly connected to a first source of reference voltage (+V), the other output electrodes of said first and second transistors are commonly connected to said variable current source (53), said variable current source (53) is connected to said external terminal (lld) connected to said variable control means, the base electrode of said first transistor (51) is connected to said high frequency circuit (12); a bias source (54,55) is connected to the base electrode of said second transistor (52) such that the same operates as a base grounded type, and wherein said semiconductor impedance element is constituted by said diffusion capacitance of each said first and second transistors (51,52).

Claim 11

A monolithic integrated circuit device according to claim 7 or claim 8 characterised in that said AC negative feedback circuit (14) comprises: . . first and second said transistors (51,54) each having a plurality of output electrodes and a base electrode; and a current source (55), first output electrodes of said first and second transistors are commonly connected to a source of reference voltage (13), the other output electrodes of the first and second transistors are commonly connected to said current source (55), the base electrode of said first transistor (51) is connected to said high frequency circuit (12), the base electrode of said second transistor (54) is connected to said external terminal (lld) connected to said variable control means, and said semiconductor impedance element is constituted by said diffusion capacitance of each of said first and second transistors.

Claim 12

A monolithic integrated circuit according to claim 1 or claim 7 or claim 8 characterised in that said AC negative feedback circuit (14) includes: first and second transistors (51,57), and a resistor (56), an output electrode of said first transistor (51) and said resistor (56) are connected in series between first and second voltage sources (13,llc), a base electrode of said first transistor (51) is connected to the high frequency circuit (12), an output electrode of said second transistor (57) is connected in parallel with said resistor (56), and a base electrode of said second transistor is connected to said external terminal (lld) connected to said vari- .. able control means.

Claim 13

A monolithic integrated circuit device according to claim 7 or claim 8 characterised in that said high frequency amplifier circuit (12) comprises: two sets of serially connected members each set including a load resistor (32A,32B), a transistor (31A,31B) and a DC negative feedback resistor (33A,33B); and a current source (35) connected between a junction between respective DC negative feedback resistors and a source of reference voltage (llc), and wherein said AC negative feedback circuit (14) comprises: first and second transistors (51A,51B) each having a plurality of output electrodes, and a variable current source (53), first output electrodes of said first and second transistors are commonly connected to a source of reference voltage (13), the other output electrodes of said first and second transistors are commonly connected to said variable current source (53) which is connected to said external terminal (lld) connected to said variable control means, and base electrodes of said first and second transistors (51A,51B) are connected between a respective said transistor (31A,31B) of said high frequency amplifier circuit and a respective said DC negative feedback resistor (33A,33B).

Claim 14

A monolithic integrated circuit device according to any one of claims 9,10 and 12 characterised in that said current source comprises a transist or.

Claim 15

A monolithic integrated circuit according to claim 1 characterised in that said semiconductor 'impedance element is constituted by a differentiated resistance of a diode (62).

Claim 16

A monolithic integrated circuit device according to claim 14 characterised in that said AC negative feedback circuit (14) comprises: said diode (62) and a variable current source (63) which are connected in series between first and second voltage sources (T2 and T3); and a capacitor (61) with one side connected to a junction between said diode and said variable current source and the other side connected to said high frequency amplifier circuit (12), and wherein said variable current source (63) is connected to said external terminal (lld) connected to said variable control device.

Claim 17

A monolithic integrated circuit device according to claim 15 characterised in that said high frequency amplifier circuit (12) comprises: a transistor (31) including base, collector and emitter electrodes; means (lla) for applying an input signal to said base electrode; a load resistor (32) connected between a first source (13) of reference voltage and said collector electrode; and a DC negative feedback resistor (33) connected between a second source of reference voltage (llc) and said emitter electrode, and wherein said capacitor (61) in said AC negative feedback circuit is connected to said emitter electrode.

Claim 18

A monolithic integrated circuit device according to claim 15 characterised in that said high frequency amplifier circuit (12) comprises: two sets of serially connected members each including a load resistor (32A,32B), a transistor (31A,31B) and a DC negative feedback resistor (33A,33B); a current source (35) connected between commonly connected first ends of the respective DC negative feedback resistors and a second source of reference voltage (llc), and wherein said AC negative feedback circuit (14) comprises: first and second capacitors (61A,61B); first and second diodes (62A,62B); and first and second variable current sources (63A, 63B), said first diode and said first variable current source, and said second diode and said second variable current source, are each connected in series between a first source of reference voltage (13) and said second voltage source (llc), first sides of said first and second capacitors are connected to the junctions between said first and second diodesa-dsaid first and second variable current sources respectively, the other sides of said first and second capacitors are connected to junctions between said transistors and said DC negative feedback resistors respectively, and said first and second variable current sources are commonly connected to said external terminal (lld) connected to said variable control means.