Routing YIG-tuned mixer

• US 5,553,319 A
• Filed: 01/23/1995
• Issued: 09/03/1996
• Est. Priority Date: 07/29/1992
• Status: Expired due to Term

• Current Assignee: Agilent Technologies, Inc.
• Original Assignee: Hewlett-Packard Company (HP Inc.)
• Inventors: Tanbakuchi, Hassan
• Primary Examiner(s): Eisenzopf, Reinhard J.
• Assistant Examiner(s): LE, THANH C
• Application Number:
  US08/378,884
• Time in Patent Office: 589 Days
• Field of Search: 455/197.1, 455/323, 455/316, 455/317, 455/318, 455/325, 455/326, 455/333, 455/319, 455/330, 332/173, 333/202
• US Class Current: 455/326
• CPC Class Codes: H03D 7/1408 with diodes
• CPC Class Codes: H03D 9/0608 by means of diodes
• CPC Class Codes: H03J 3/16 Tuning without displacement of reactive element, e.g. by varying permeability

Abstract

A routing YIG-tuned resonator filter integrated with an image-enhanced, double-balanced mixer. The YIG-tuned resonator filter is preferably a four-sphere YIG-tuned preselector which is integrated with a low-loss, fundamentally or harmonically mixed, image-enhanced, double-balanced mixer to provide a high level of dynamic range in a harmonically mixed front end. An input resonator of the preselector in combination with a dual PIN diode switch switches low-frequency input signals (e.g., 0 to 2.9 GHz) to a low-band mixer. For RF input signals (e.g., 2.7 to 26.5 GHz), the four-sphere YIG-tuned preselector is combined with the image-enhanced, double-balanced mixer which incorporates a GaAs monolithic diode bridge integrated circuit. This provides a cost effective front end for a microwave spectrum analyzer.

Claims

1. A frequency-tunable resonator filter and mixer to provide a tunable bandpass filter and image-enhanced, double-balanced mixer in response to a radio-frequency (RF) input signal having a given frequency at an RF input, comprising:

at least one frequency-tunable resonator, comprising;

an input coupling loop coupled to the RF input for receiving the RF input signal;

a ferrimagnetic sphere proximate to the input coupling loop; and

an output coupling loop proximate to the ferrimagnetic sphere for receiving the RF input signal when a resonance frequency of the at least one frequency-tunable resonator approximates the given frequency of the RF input signal, the output coupling loop being terminated at a first end by a first intermediate-frequency (IF) balun having an input connected to the first end of the output coupling loop to provide an even harmonic IF balun, the output of the first IF balun being connected to an even IF port, and the output coupling loop being terminated at a second end by a diode bridge comprising four diodes;

an electromagnet for producing a DC magnetic field that is uniform over the at least one frequency-tunable resonator for tuning the resonance frequency of the at least one frequency-tunable resonator;

first and second capacitors connected between the respective junctions of the output coupling loop and the first IF balun, on the one hand, and ground, on the other hand;

third and fourth capacitors connected in series across the outputs of the diode bridge;

a swept local oscillator (LO) input for generating an LO signal, the junction between the third and fourth capacitors being connected to the LO input;

first and second inductors having first ends connected to the respective junctions of the diode bridge and the third and fourth capacitors, respectively; and

a second IF balun having an input connected across second ends of the first and second inductors to provide a fundamental and odd harmonic IF balun, an output of the second IF balun being connected to an odd IF port;

wherein the frequency-tunable resonator filter and mixer provides one of odd and even harmonic mixing.

2. The frequency-tunable resonator filter and mixer in accordance with claim 1, further comprising a routing circuit for routing low-frequency input signals to a low-frequency output and high-frequency input signals to the output coupling loop, wherein the input coupling loop has a first end coupled to the RF input and a second end, the routing circuit comprising:

a first transmission line and a second transmission line connected in series between the second end of the input coupling loop and the low-frequency output;

a fifth capacitor and a first diode connected in series between ground and the junction of the RF input and first transmission line;

a sixth capacitor and a second diode connected in series between ground and the junction of the first and second transmission lines; and

a bias network, comprising;

a first resistor having a first end connected to the junction of the fifth capacitor and first diode and a second resistor having a first end connected to the junction of the sixth capacitor and second diode, each of the first and second resistors having a second end connected to a first end of a third resistor;

a third inductor having a first end connected to a second end of the third resistor;

a seventh capacitor connected between a second end of the third inductor and ground; and

a bias voltage selectively connected to the second end of the third inductor for simultaneously biasing the first and second diodes "on" to route the high-frequency input signals to the output coupling loop.

3. The frequency-tunable resonator filter and mixer in accordance with claim 2, further comprising:

a second frequency-tunable resonator having an input coupled to the RF input and an output to provide a first stage of the filter;

a third frequency-tunable resonator having an input coupled to the output of the second frequency-tunable resonator and an output to provide a second stage of the filter; and

a fourth frequency-tunable resonator having an input coupled to the output of the third frequency-tunable resonator and an output to provide a third stage of the filter;

wherein the electromagnet produces a DC magnetic field that is uniform over the frequency-tunable resonators for tuning the resonance frequency of the resonators; and

wherein the input coupling loop of the at least one frequency-tunable resonator is coupled to the output of the fourth frequency-tunable resonator to provide a fourth stage of the filter, as well as an image-enhanced, double-balanced mixer.

4. The frequency-tunable resonator filter and mixer in accordance with claim 2, wherein the output coupling loop is terminated at the first end by an eighth capacitor connected in parallel with the input of the first IF balun, further comprising:

a ninth capacitor connected across the diode bridge; and

tenth and eleventh capacitors connected between the respective junctions of the first inductor and the second IF balun and the second inductor and the second IF balun, on the one hand, and ground, on the other hand.

5. The frequency-tunable resonator filter and mixer in accordance with claim 4, further comprising:

a second frequency-tunable resonator having an input coupled to the RF input and an output to provide a first stage of the filter;

a third frequency-tunable resonator having an input coupled to the output of the second frequency-tunable resonator and an output to provide a second stage of the filter; and

a fourth frequency-tunable resonator having an input coupled to the output of the third frequency-tunable resonator and an output to provide a third stage of the filter;

wherein the electromagnet produces a DC magnetic field that is uniform over the frequency-tunable resonators for tuning the resonance frequency of the resonators; and

wherein the input coupling loop of the at least one frequency-tunable resonator is coupled to the output of the fourth frequency-tunable resonator to provide a fourth stage of the filter, as well as an image-enhanced, double-balanced mixer.

6. The frequency-tunable resonator filter and mixer in accordance with claim 1, wherein the output coupling loop is terminated at the first end by a fifth capacitor connected in parallel with the input of the first IF balun, further comprising:

a sixth capacitor connected across the diode bridge; and

seventh and eighth capacitors connected between the respective junctions of the first inductor and the second IF balun and the second inductor and the second IF balun, on the one hand, and ground, on the other hand.

7. The frequency-tunable resonator filter and mixer in accordance with claim 6, further comprising:

an IF switch for selectively switching to one of the odd and even IF ports to provide one of odd and even harmonic mixing, respectively.

8. The frequency-tunable resonator filter and mixer in accordance with claim 7, further comprising:

a second frequency-tunable resonator having an input coupled to the RF input and an output to provide a first stage of the filter;

a third frequency-tunable resonator having an input coupled to the output of the second frequency-tunable resonator and an output to provide a second stage of the filter; and

a fourth frequency-tunable resonator having an input coupled to the output of the third frequency-tunable resonator and an output to provide a third stage of the filter;

wherein the electromagnet produces a DC magnetic field that is uniform over the frequency-tunable resonators for tuning the resonance frequency of the resonators; and

wherein the input coupling loop of the at least one frequency-tunable resonator is coupled to the output of the fourth frequency-tunable resonator to provide a fourth stage of the filter, as well as an image-enhanced, double-balanced mixer.

9. The frequency-tunable resonator filter and mixer in accordance with claim 6, further comprising:

a second frequency-tunable resonator having an input coupled to the RF input and an output to provide a first stage of the filter;

a third frequency-tunable resonator having an input coupled to the output of the second frequency-tunable resonator and an output to provide a second stage of the filter; and

a fourth frequency-tunable resonator having an input coupled to the output of the third frequency-tunable resonator and an output to provide a third stage of the filter;

wherein the electromagnet produces a DC magnetic field that is uniform over the frequency-tunable resonators for tuning the resonance frequency of the resonators; and

wherein the input coupling loop of the at least one frequency-tunable resonator is coupled to the output of the fourth frequency-tunable resonator to provide a fourth stage of the filter, as well as an image-enhanced, double-balanced mixer.

10. The frequency-tunable resonator filter and mixer in accordance with claim 1, further comprising:

an IF switch for selectively switching to one of the odd and even IF ports to provide one of odd and even harmonic mixing, respectively.

11. The frequency-tunable resonator filter and mixer in accordance with claim 1, further comprising:

a second frequency-tunable resonator having an input coupled to the RF input and an output to provide a first stage of the filter;

a third frequency-tunable resonator having an input coupled to the output of the second frequency-tunable resonator and an output to provide a second stage of the filter; and

a fourth frequency-tunable resonator having an input coupled to the output of the third frequency-tunable resonator and an output to provide a third stage of the filter;

wherein the electromagnet produces a DC magnetic field that is uniform over the frequency-tunable resonators for tuning the resonance frequency of the resonators; and

wherein the input coupling loop of the at least one frequency-tunable resonator is coupled to the output of the fourth frequency-tunable resonator to provide a fourth stage of the filter, as well as an image-enhanced, double-balanced mixer.

12. A frequency-tunable resonator filter and mixer to provide a tunable bandpass filter and image-enhanced, double-balanced mixer in response to a radio-frequency (RF) input signal having a given frequency at an RF input, comprising:

at least one frequency-tunable resonator, comprising;

an input coupling loop coupled to the RF input for receiving the RF input signal;

a ferrimagnetic sphere proximate to the input coupling loop; and

an output coupling loop proximate to the ferrimagnetic sphere for receiving the RF input signal when a resonance frequency of the at least one frequency-tunable resonator approximates the given frequency of the RF input signal, the output coupling loop being continuous at a first end and the output coupling loop being terminated at a second end by a diode bridge comprising four diodes;

an electromagnet for producing a DC magnetic field that is uniform over the at least one frequency-tunable resonator for tuning the resonance frequency of the at least one frequency-tunable resonator;

a swept local oscillator (LO) input connected to the first end of the output coupling loop for generating an LO signal;

an intermediate-frequency (IF) balun having an input connected across the diode bridge to provide a fundamental and odd harmonic IF balun, an output of the IF balun being connected to an odd IF port; and

first and second capacitors connected between the respective junctions of the diode bridge and the IF balun, on the one hand, and ground, on the other hand;

wherein the frequency-tunable resonator filter and mixer mixes one of a fundamental and odd harmonic products of the LO signal with the RF input signal to produce a predetermined low-frequency IF signal output.

13. The frequency-tunable resonator filter and mixer in accordance with claim 12, further comprising a routing circuit for routing low-frequency input signals to a low-frequency output and high-frequency input signals to the output coupling loop, wherein the input coupling loop has a first end coupled to the RF input and a second end, the routing circuit comprising:

a first transmission line and a second transmission line connected in series between the second end of the input coupling loop and the low-frequency output;

a third capacitor and a first diode connected in series between ground and the junction of the RF input and first transmission line;

a fourth capacitor and a second diode connected in series between ground and the junction of the first and second transmission lines; and

a bias network, comprising;

a first resistor having a first end connected to the junction of the third capacitor and first diode and a second resistor having a first end connected to the junction of the fourth capacitor and second diode, each of the first and second resistors having a second end connected to a first end of a third resistor;

an inductor having a first end connected to a second end of the third resistor;

a fifth capacitor connected between a second end of the inductor and ground; and

a bias voltage selectively connected to the second end of the inductor for simultaneously biasing the first and second diodes "on" to route the high-frequency input signals to the output coupling loop.

14. The frequency-tunable resonator filter and mixer in accordance with claim 12, further comprising:

a second frequency-tunable resonator having an input coupled to the RF input and an output to provide a first stage of the filter;

a third frequency-tunable resonator having an input coupled to the output of the second frequency-tunable resonator and an output to provide a second stage of the filter; and

a fourth frequency-tunable resonator having an input coupled to the output of the third frequency-tunable resonator and an output to provide a third stage of the filter;

wherein the electromagnet produces a DC magnetic field that is uniform over the frequency-tunable resonators for tuning the resonance frequency of the resonators; and

wherein the input coupling loop of the at least one frequency-tunable resonator is coupled to the output of the fourth frequency-tunable resonator to provide a fourth stage of the filter, as well as an image-enhanced, double-balanced mixer.

15. The frequency-tunable resonator filter and mixer in accordance with claim 12, further comprising:

a third capacitor connected across the diode bridge.

16. A frequency-tunable resonator filter and mixer to provide a tunable bandpass filter and image-enhanced, double-balanced mixer in response to a radio-frequency (RF) input signal having a given frequency at an RF input, comprising:

at least one frequency-tunable resonator, comprising;

an input coupling loop coupled to the RF input for receiving the RF input signal;

a ferrimagnetic sphere proximate to the input coupling loop; and

an output coupling loop proximate to the ferrimagnetic sphere for receiving the RF input signal when a resonance frequency of the at least one frequency-tunable resonator approximates the given frequency of the RF input signal, the output coupling loop being continuous at a first end and connected to ground and the output coupling loop being terminated at a second end by a diode bridge comprising four diodes;

an electromagnet for producing a DC magnetic field that is uniform over the at least one frequency-tunable resonator for tuning the resonance frequency of the at least one frequency-tunable resonator;

first and second capacitors connected in series across the diode bridge;

a swept local oscillator (LO) input for generating an LO signal, the junction between the first and second capacitors being connected to the LO input;

first and second inductors having first ends connected to the respective junctions of the diode bridge and the first and second capacitors; and

an intermediate-frequency (IF) balun having an input connected across second ends of the first and second inductors to provide a fundamental and odd harmonic IF balun, an output of the IF balun being connected to an odd IF port;

wherein the frequency-tunable resonator filter and mixer mixes one of a fundamental and odd harmonic products of the LO signal with the RF input signal to produce a predetermined low-frequency IF signal output.

17. The frequency-tunable resonator filter and mixer in accordance with claim 16, further comprising a routing circuit for routing low-frequency input signals to a low-frequency output and high-frequency input signals to the output coupling loop, wherein the input coupling loop has a first end coupled to the RF input and a second end, the routing circuit comprising:

a first transmission line and a second transmission line connected in series between the second end of the input coupling loop and the low-frequency output;

a third capacitor and a first diode connected in series between ground and the junction of the RF input and first transmission line;

a fourth capacitor and a second diode connected in series between ground and the junction of the first and second transmission lines; and

a bias network, comprising;

a first resistor having a first end connected to the junction of the third capacitor and first diode and a second resistor having a first end connected to the junction of the fourth capacitor and second diode, each of the first and second resistors having a second end connected to a first end of a third resistor;

a third inductor having a first end connected to a second end of the third resistor;

a fifth capacitor connected between a second end of the third inductor and ground; and

a bias voltage selectively connected to the second end of the third inductor for simultaneously biasing the first and second diodes "on" to route the high-frequency input signals to the output coupling loop.

18. The frequency-tunable resonator filter and mixer in accordance with claim 16, further comprising:

a second frequency-tunable resonator having an input coupled to the RF input and an output to provide a first stage of the filter;

a third frequency-tunable resonator having an input coupled to the output of the second frequency-tunable resonator and an output to provide a second stage of the filter; and

a fourth frequency-tunable resonator having an input coupled to the output of the third frequency-tunable resonator and an output to provide a third stage of the filter;

wherein the electromagnet produces a DC magnetic field that is uniform over the frequency-tunable resonators for tuning the resonance frequency of the resonators; and

wherein the input coupling loop of the at least one frequency-tunable resonator is coupled to the output of the fourth frequency-tunable resonator to provide a fourth stage of the filter, as well as an image-enhanced, double-balanced mixer.

19. The frequency-tunable resonator filter and mixer in accordance with claim 16, further comprising:

a third capacitor connected across the diode bridge; and

fourth and fifth capacitors connected between the second ends of the first and second inductors, respectively, and ground.

20. A frequency-tunable resonator filter and mixer to provide a tunable bandpass filter and image-enhanced, double-balanced mixer in response to a radio-frequency (RF) input signal having a given frequency at an RF input, comprising:

at least one frequency-tunable resonator, comprising;

an input coupling loop coupled to the RF input for receiving the RF input signal;

a ferrimagnetic sphere proximate to the input coupling loop; and

an output coupling loop proximate to the ferrimagnetic sphere for receiving the RF input signal when a resonance frequency of the at least one frequency-tunable resonator approximates the given frequency of the RF input signal, the output coupling loop being terminated at a first end by an intermediate-frequency (IF) balun having an input connected to the first end of the output coupling loop to provide an even harmonic IF balun, an output of the IF balun being connected to an even IF port, and the output coupling loop being terminated at a second end by a diode bridge comprising four diodes;

an electromagnet for producing a DC magnetic field that is uniform over the at least one frequency-tunable resonator for tuning the resonance frequency of the at least one frequency-tunable resonator;

a swept local oscillator (LO) input connected across the diode bridge for generating an LO signal; and

first and second capacitors connected between the respective junctions of the output coupling loop and the IF balun, on the one hand, and ground, on the other hand;

wherein the frequency-tunable resonator filter and mixer mixes even harmonic products of the LO signal with the RF input signal to produce a predetermined low-frequency IF signal output.

21. The frequency-tunable resonator filter and mixer in accordance with claim 20, further comprising a routing circuit for routing low-frequency input signals to a low-frequency output and high-frequency input signals to the output coupling loop, wherein the input coupling loop has a first end coupled to the RF input and a second end, the routing circuit comprising:

a first transmission line and a second transmission line connected in series between the second end of the input coupling loop and the low-frequency output;

a third capacitor and a first diode connected in series between ground and the junction of the RF input and first transmission line;

a fourth capacitor and a second diode connected in series between ground and the junction of the first and second transmission lines; and

a bias network, comprising;

a first resistor having a first end connected to the junction of the third capacitor and first diode and a second resistor having a first end connected to the junction of the fourth capacitor and second diode, each of the first and second resistors having a second end connected to a first end of a third resistor;

an inductor having a first end connected to a second end of the third resistor;

a fifth capacitor connected between a second end of the inductor and ground; and

a bias voltage selectively connected to the second end of the inductor for simultaneously biasing the first and second

diodes "on" to route the high-frequency input signals to the output coupling loop.

22. The frequency-tunable resonator filter and mixer in accordance with claim 20, further comprising:

a second frequency-tunable resonator having an input coupled to the RF input and an output to provide a first stage of the filter;

a third frequency-tunable resonator having an input coupled to the output of the second frequency-tunable resonator and an output to provide a second stage of the filter; and

a fourth frequency-tunable resonator having an input coupled to the output of the third frequency-tunable resonator and an output to provide a third stage of the filter;

wherein the electromagnet produces a DC magnetic field that is uniform over the frequency-tunable resonators for tuning the resonance frequency of the resonators; and

wherein the input coupling loop of the at least one frequency-tunable resonator is coupled to the output of the fourth frequency-tunable resonator to provide a fourth stage of the filter, as well as an image-enhanced, double-balanced mixer.

23. The frequency-tunable resonator filter and mixer in accordance with claim 20, wherein the output coupling loop is terminated at the first end by a third capacitor.