High Q-factor oscillator circuit
AssigneeRaytheon Company
InventorCheng P. Wen
Life of this patent
Estimating the term…
Abstract
A millimeter-wave/microwave oscillator circuit and method of fabricating same are disclosed. A high Q-factor resonator is formed by disposing a transferred electron negative resistance device, such as a Gunn diode, or an IMPATT negative resistance device in a semi-circular cross-sectional shaped resonator cavity. The equivalent capacitance of the negative resistance diode can be designed to resonate with the equivalent series inductance for the resonator cavity by adjusting the dimensions of the cavity and the placement of the negative resistance device therein. Very low cost, compact and lightweight microwave and millimeter-wave integrated circuit power sources using negative resistance diodes can be batch manufactured.
Claims12
A millimeter-wave/microwave oscillator circuit, comprising:
- a substrate;
- a transmission line disposed in a first portion of said substrate for radiating oscillator signals at an oscillator signal frequency;
- a resonator cavity disposed in a second portion of said substrate and coupled to said transmission line, the resonator cavity having an equivalent inductance;
- a negative resistance diode coupled to said transmission line and disposed in said resonator cavity, the negative resistance diode having an equivalent capacitance and an equivalent resistance substantially resonant with said equivalent inductance of said resonator cavity;
- and
- an RF impedance transformer segment disposed in a third portion of said substrate and coupled to said cavity and said transmission line for impedance matching between said transmission line and said cavity.
A method of fabricating a millimeter-wave/microwave oscillator circuit having a substrate, said method comprising the steps of:
- etching a first plane in said substrate;
- etching a second plane in said substrate;
- depositing conductive material on the first and second planes to form a transmission line;
- etching a resonator cavity in said substrate coupled to said transmission line;
- depositing conductive material on surfaces defining the resonator cavity;
- disposing a negative resistance diode in said resonator cavity;
- and
- electrically connecting the negative resistance diode to the transmission line.
A method of fabricating a millimeter-wave/microwave oscillator circuit, said method comprising the steps of:
- providing upper and lower substrate portions;
- forming a first portion of a transmission line in said lower substrate portion;
- forming a first portion of a resonator cavity in said lower substrate portion;
- forming a second portion of said resonator cavity in said upper substrate portion:
- forming a second portion of said transmission line in said upper substrate portion;
- forming an RF impedance transformer segment in said upper substrate portion, wherein said RF impedance transformer segment is coupled in series between said second portion of said transmission line and said second portion of said resonator cavity;
- disposing a negative resistance diode in said first portion of said resonator cavity;
- connecting said negative resistance diode to said first portion of said transmission line and to said first portion of said resonator cavity;
- and
- coupling said upper substrate portion to said lower substrate portion.
A negative resistance diode oscillator, comprising;
- a transmission line;
- a resonator cavity with a semi-circular cross-sectional shape with a height H and a radius R2, wherein said cavity has an equivalent inductance L;
- an impedance matching segment coupled between said cavity and said transmission line for providing an impedance match between said cavity and said transmission line;
- a negative resistance diode coupled to said cavity at a distance R1 from a planar wall of the cavity such that an equivalent capacitance C of said negative resistance diode is resonant with said inductance L at said oscillator frequency,
- wherein the inductance L is substantially equal to:
- L.apprxeq.60*(H/R1)*tan(k*(R2-R1)),
- with k being a wave number.
Dependencies are inferred from the claim text.