Microwave frequency divider having regenerative oscillation

• US 4,631,500 A
• Filed: 04/24/1984
• Issued: 12/23/1986
• Est. Priority Date: 04/24/1984
• Status: Expired due to Fees

• Current Assignee: the united states of america as represented by the secretary of the navy
• Original Assignee: the united states of america as represented by the secretary of the navy
• Inventors: Rauscher, Christen
• Primary Examiner(s): LaRoche, Eugene R.
• Assistant Examiner(s): Lee, Benny T.
• Application Number:
  US06/603,382
• Time in Patent Office: 973 Days
• Field of Search: 333/218, 307/219.1, 307/271, 328/15, 328/16, 328/25, 331/51, 331/117 FE, 363/157, 363/158, 363/159, 455/321, 455/333
• US Class Current: 331/51
• CPC Class Codes: H03B 5/00 Generation of oscillations using amplifier with regenerative feedback from output to input H03B9/00, H03B15/00 take precedence
• CPC Class Codes: H03D 11/04 by means of semiconductor devices having more than two electrodes
• CPC Class Codes: H03D 7/125 with field effect transistors

Abstract

A microwave frequency divider circuit. The frequency divider comprises a nonlinear amplifier including input and output ports for amplifying signals applied to the input port. The amplifier exhibits a nonlinear transconductance characteristic between its input and output ports. The amplifier input port is adaptable to receive a first signal having a frequency f_l. The frequency divider further includes a feedback network coupled between the amplifier output and input ports to couple a second signal having a frequency f_o appearing at the amplifier output port back to the input port. The first and second signals combine at the amplifier input port to modulate the nonlinear transconductance of the amplifier such that said first and second signals are mixed together and amplified. The circuit regeneratively oscillates such that the frequency f_o equals a frequency f_l /2. The frequency f_l of the first signal is thus divided by the circuit.

Claims

1. A regeneratively oscillating broadband microwave frequency divider circuit comprising:

nonlinear amplifier means for amplifying signals including a three-electrode field effect transistor connected between an input port and an output port, said field effect transistor exhibiting a nonlinear transconductance characteristic, said input port being adapted to receive a first signal having a frequency f₁ ;

said three electrode field effect transistor comprising a gate electrode, a drain electrode, and a source electrode, and being configured as a common source amplifier, said gate electrode forming said input port of said amplifier means and said drain electrode forming said output port of said amplifier means;

biasing means coupled to all three of said electrodes of said field-effect transistor for biasing said transistor at or just short of pinch off such that said field-effect transistor exhibits said nonlinear transconductance characteristic;

feedback means connected across two of said three electrodes of said field effect transistor between said output port and said input port of said nonlinear amplifier means for coupling a second signal having a frequency f_o that is half said frequency f₁ from said output port to said input port of said nonlinear amplifier means, said first and second signals combining at said input port to modulate said nonlinear transconductance characteristic of said field effect transistor such that said first and second signals are mixed together and amplified in said field effect transistor to produce said second signal having a frequency f_o that is half said frequency f, said feedback means comprising an inductor and a d.c. blocking capacitor coupled in a nonresonant series circuit between said gate electrode and said drain electrode of said field-effect transistor;

whereby said frequency f₁ of said first signal is divided in half by said circuit to produce said frequency f_o of said second signal.

2. A regeneratively oscillating broadband microwave frequency divider circuit comprising:

a field-effect transistor having only three electrodes including a gate electrode, a drain electrode, and a source electrode, said field effect transistor being configured as a common source amplifier, said gate electrode being adapted to receive a first signal having a frequency f₁ ;

biasing means coupled to all three of said electrodes of said field-effect transistor for biasing said field-effect transistor at or just short of pinch-off such that said field effect transistor exhibits a nonlinear transconductance characteristic; and

feedback means coupled between said drain electrode and said gate electrode of said field-effect transistor for coupling a second output signal having a frequency f_o from said drain electrode back to said gate electrode, said feedback means comprising an inductor and a d.c. blocking capacitor coupled in a nonresonant series circuit between said gate electrode and said drain electrode of said field-effect transistor;

said first and second signals combining at said gate electrode to modulate said nonlinear transconductance characteristic of said field-effect transistor such that said first and second signals are mixed together and amplifed in said field-effect transistor, said frequency f_o being one half said frequency f₁,

whereby said frequency f₁ of said first signal is divided in half by said divider circuit.