Adjustable phase and delay shift element

• US 6,335,665 B1
• Filed: 09/28/1999
• Issued: 01/01/2002
• Est. Priority Date: 09/28/1999
• Status: Expired due to Term

• Current Assignee: Lucent Technologies, Inc. (Nokia Corporation)
• Original Assignee: Lucent Technologies, Inc. (Nokia Corporation)
• Inventors: Mendelsohn, Joseph Patrick
• Primary Examiner(s): Pascal, Robert
• Assistant Examiner(s): Glenn, Kimberly E
• Application Number:
  US09/406,919
• Time in Patent Office: 826 Days
• Field of Search: 333/139, 333/161, 333/164, 333/156, 333/109, 333/117
• US Class Current: 333/139
• CPC Class Codes: H01P 1/185 using a diode or a gas filled discharge tube
• CPC Class Codes: H01P 9/00 Delay lines of the waveguide type

Abstract

An apparatus and method provide an adjustable phase and time delay to an input signal. The apparatus includes an inverting element and first and second variable capacitors. The inverting element has a first end serially coupled with the input signal and a second end. The first variable capacitor is coupled between the first end of the inverting element and first voltage. The second variable capacitor is coupled between the second end of the inverting element and a second voltage. The first and second variable capacitors are separately adjustable to controllably vary a phase shift and a delay of a reflection of the input signal. The first and second voltages may be at the same or different potentials.

The input signal may be coupled to the inverting element through a directional coupler, such as a circulator. The input signal, which is reflected by the inverting element, may be coupled back through the directional coupled and output as the output signal having a desired phase shift and delay relative to the input signal.

Claims

1. An apparatus for providing an adjustable phase shift and delay to a signal, comprising:

an inverting element having first and second ends, the first end serially coupled with an input signal;

first and second variable capacitors coupled to the first end and the second end, respectively; and

first and second adjustable voltage sources associated with the first and second variable capacitors, respectively, for adjusting a voltage applied across the first and second variable capacitors,

wherein the first and second variable capacitors are separately adjustable to controllably vary a phase and a delay of a reflection of the input signal.

2. The apparatus according to claim 1, wherein the inverting element is a quarter wavelength transmission line.

3. The apparatus according to claim 1, wherein the inverting element includes lumped element components.

4. The apparatus according to claim 1, wherein the capacitors are mechanically adjustable capacitors and the first and second voltages are at the same potential.

5. The apparatus according to claim 1, wherein the capacitors are adjusted to different values in order to realize a desired phase shift and delay.

6. The apparatus according to claim 1, further comprising:

a directional coupler having first, second and third ports, the first port being coupled with the input signal, the second port being coupled with the first end and the third port conveying the output signal, the directional coupler conveying the input signal applied at the first port to the second port and conveying the reflection of the input signal applied at the second port to the third port.

7. The apparatus according to claim 6, further comprising:

first and second fixed capacitors, the first fixed capacitor being coupled between the second port and the first end and the second fixed capacitor being coupled between the second end and the second variable capacitor.

8. The apparatus according to claim 1, further comprising:

a second inverting element having third and fourth ends;

a directional coupler having first, second, third and fourth ports, the directional coupler conveying signals applied at the third port to the fourth port;

third and fourth variable capacitors coupled to the third and fourth ends, respectively; and

third and fourth adjustable voltage sources associated with the third and fourth variable capacitors, respectively, for adjusting a voltage applied across the third and fourth variable capacitors,

wherein the third and fourth variable capacitors are separately adjustable to controllably vary a phase and delay of the input signal emanating from the third port.