Methods and apparatuses for reflection measurements

Patent metadata

Field	Value
Publication number	US-11646702-B2
Application number	US-202117350772-A
Country	US
Kind code	B2
Filing date	Jun 17, 2021
Priority date	Nov 5, 2018
Publication date	May 9, 2023
Grant date	May 9, 2023

Abstract

Techniques are provided to more accurately determine reflected power, reflection coefficient, and/or voltage standing wave to permit prompt protection of components such as power amplifiers and notify communication system operators. This is accomplished by more accurately determining an amplitude and phase of an output reflected signal at an output port of a bidirectional coupler as a function of the following: an amplitude and a phase of a coupled forward signal coupled into a forward coupled port of the bidirectional coupler; an amplitude and a phase of a coupled reverse signal coupled into a reverse coupled port of the bidirectional coupler; an electrical transmission parameter from an input port of the bidirectional coupler to the forward coupled port; an electrical transmission parameter from the input port to the reverse coupled port; and an electrical transmission parameter from an output port of the bidirectional coupler to the reverse coupled port.

First claim

The invention claimed is:

1. A method, comprising:
measuring amplitude and phase of a coupled forward signal at a forward coupled port of a bidirectional coupler;
measuring an amplitude and a phase of a coupled reverse signal at a reverse coupled port of the bidirectional coupler; and
determining an amplitude and a phase of an output reflected signal at an output port of the bidirectional coupler as a function of:
the amplitude and the phase of the coupled forward signal coupled into the forward coupled port; and
the amplitude and the phase of the coupled reverse signal coupled into the reverse coupled port.

2. The method of claim 1 , wherein determining an amplitude and phase of the output reflected signal at the output port is determined with S-parameters according to:

b
4

-

(

b
3

S

3
⁢
1

*

S

4
⁢
1

)

S

4
⁢
2

;

where b 3 is the coupled forward signal coupled into the forward coupled port;
where b 4 is the coupled reverse signal coupled into the reverse coupled port;
where S 31 is a transmission S-parameter from an input port of the bidirectional coupler to the forward coupled port;
where S 41 is a transmission S-parameter from the input port to the reverse coupled port; and
where S 42 is a transmission S-parameter from the output port of the bidirectional coupler to the reverse coupled port.

3. The method of claim 1 , further comprising:
determining if at least one of an output reflected power exceeds a reflected power threshold and a coupled reverse power exceeds a coupled reverse power threshold; and
if at least one of the output reflected power exceeds the reflected power threshold and the coupled reverse power exceeds the coupled reverse power threshold, then performing at least one of: reducing a power level of an input signal at an input port of the bidirectional coupler until at least one of the output reflected power is less than or equal to the reflected power threshold and the coupled reverse power is less than or equal to the coupled reverse power threshold, and providing an alarm indicating that at least one of the output reflected power exceeds a reflected power threshold and the coupled reverse power exceeds the coupled reverse power threshold.

4. The method of claim 3 , wherein reducing the power level of the input signal comprises reducing a power level of an output signal of a signal source that is a power amplifier having an output coupled to the input port.

5. The method of claim 1 , further comprising:
determining at least one of a reflection coefficient (Γ) at the output port and a voltage standing wave ratio (VSWR) at the output port, where the reflection coefficient and the voltage standing wave ratio are determined for a load coupled to the output port, and where:
the reflection coefficient is a function of the output reflected signal; and

VSWR
=

1
+

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r

❘
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1
-

❘
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r

❘
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.

6. The method of claim 5 , further comprising:
determining if at least one of the reflection coefficient exceeds a reflection coefficient threshold and the VSWR exceeds a VSWR threshold; and
if at least one of the reflection coefficient exceeds the reflection coefficient threshold and the VSWR exceeds the VSWR threshold, then providing an alarm indicating that at least one of: the reflection coefficient exceeds the reflection coefficient threshold and the VSWR exceeds the VSWR threshold.

7. The method of claim 1 , wherein further comprising:
determining if at least one of an input power at an input port is equal to or exceeds an input power threshold, and a coupled forward power is equal to or exceeds a coupled forward power threshold; and
if at least one of the input power is equal to or exceeds the input power threshold and the coupled forward power is equal to or exceeds the coupled forward power threshold, performing at least one of: reducing a power level of the input power until at least one of the input power at the input port less than an input power threshold and the coupled forward power is less than the coupled forward power threshold, and providing an alarm indicating an automatic limiting control function has been enabled.

8. The method of claim 7 , wherein reducing the power level of the input power comprises reducing a power level of an output signal of a signal source that is a power amplifier having an output coupled to the input port.

9. A system, comprising:
a bidirectional coupler having an input port, an output port, a forward coupled port, and a reverse coupled port, where the input port is configured to receive an input signal from a signal source coupled to the input port, and the output port is configured to provide a first output signal to a load coupled to the output port;
at least one analog to digital converter circuit having at least one input coupled to the forward coupled port and the reverse coupled port, and at least one output; and
a processing circuitry having at least one input coupled to the at least one output of the at least one analog to digital converter circuit, and an output configured to generate a second output signal related to a level of at least one of a coupled reverse signal and an output reflected signal;
wherein the processing circuitry is configured to:
measure an amplitude and a phase of a coupled forward signal at a forward coupled port of a bidirectional coupler;
measure an amplitude and a phase of a coupled reverse signal at a reverse coupled port of the bidirectional coupler; and
determine an amplitude and a phase of an output reflected signal at the output port as a function:
the am

Assignees

• Andrew Wireless Systems Gmbh

Inventors

• Gunzner Peter
• Steigert Johannes
• Lübbers Felix
• Schmid Peter
• Braun Patrick

Classifications

• H02H9/00

  Emergency protective circuit arrangements for limiting excess current or voltage without disconnection · CPC title

• H03F3/21

  with semiconductor devices only {(H03F3/245 takes precedence)} · CPC title

• H04B1/0466

  Fault detection or indication (H04B1/0483 takes precedence) · CPC title

• H02H1/0007

  concerning the detecting means (in general G01R or other subclasses of G01; reed switches H01H71/2445) · CPC title

• H03M1/12

  Analogue/digital converters ({H03M1/001 – } H03M1/10 take precedence) · CPC title