Oscillator circuit employing inductive circuit formed of field effect transistors
AssigneeSharp Kabushiki Kaisha
InventorShinji Hara
Life of this patent
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Abstract
A cascode amplifier having a 180.degree. phase characteristic is connected with in-phase feedback circuits having a 0.degree. phase characteristics. When viewed from an output side of the cascode amplifier, these circuits operate as inductive circuits having negative resistance. Thus, connecting a capacitor to the output of the cascode amplifier causes formation of a parallel resonance circuit, so that an oscillating operation is carried out. Since an inductor, i.e., inductive circuit can be structured without use of a transmission line, an occupied region necessary for formation of a microwave oscillation circuit is reduced.
Claims13
An oscillator circuit, comprising:
- an inductive circuit having a negative resistance characteristic;
- and
- capacitance means for forming a parallel resonance circuit along with said inductive circuit, wherein
- said inductive circuit includes
- first grounded source amplifier means including a first field effect transistor having a grounded source,
- grounded gate amplifier means connected to an output of said grounded source amplifier means and including a second field effect transistor having a grounded gate, and
- in-phase feedback means for feeding an output signal of said grounded gate amplifier means back in phase to said grounded source amplifier means,
- said in-phase feedback means including cascaded second and third grounded source amplifier means each including a field effect transistor having a grounded source.
An oscillator circuit, comprising:
- an inductive circuit formed of field effect transistors;
- and
- capacitance means for forming a parallel resonance circuit along with said inductive circuit, wherein
- said inductive circuit includes
- inversion amplifier means,
- impedance conversion means connected to an output of said inversion amplifier means and having a higher output impedance, and
- in-phase feedback means for feeding an output signal of said impedance conversion means back in phase to said inversion amplifier means,
- said in-phase feedback means including cascaded first and second grounded source amplifier means each including a field effect transistor having a grounded source,
- said oscillator circuit further comprising negative resistance characteristic applying means for applying a negative resistance characteristic to said inductive circuit.
Dependencies are inferred from the claim text.