US 11,029,348 B2 · Measuring a load resistance coupled to a transmission line

Abstract

Measurement circuitry is disclosed that is configured to be coupled to a load through a transmission line. A first AC signal having a frequency ω1 is applied to the transmission line and a first input impedance of the transmission line is measured. A second AC signal having a frequency ω2 is applied to the transmission line and a second input impedance of the transmission line is measured, wherein the frequency ω2 is different than the frequency ω1. A third AC signal having a frequency ω is applied to the transmission line and a third input impedance of the transmission line is measured, wherein the frequency ω is different than the frequency ω1 and different than the frequency ω2. A resistance of the load is measured based on the measured first input impedance, the measured second input impedance, and the measured third input impedance.

Claims19

Dependent claims

Measurement circuitry configured to be coupled to a load through a transmission line, wherein the measurement circuitry is configured to:

apply a first AC signal having a frequency ω1 to the transmission line and measure a first input impedance of the transmission line;
apply a second AC signal having a frequency ω2 to the transmission line and measure a second input impedance of the transmission line, wherein the frequency ω2 is different than the frequency ω1;
apply a third AC signal having a frequency ω to the transmission line and measure a third input impedance of the transmission line, wherein the frequency ω is different than the frequency ω1 and different than the frequency ω2;
and
measure a resistance of the load based on the measured first input impedance, the measured second input impedance, and the measured third input impedance,
wherein the frequency ω of the third AC signal is a quarter-wave resonance frequency of the transmission line such that a wavelength of the third AC signal is substantially equal to:
4
⁢
L
1
+
2
⁢
n
where:
L represents a length of the transmission line;
and
n is an integer.

15 more elements

A method of measuring a resistance of a load coupled through a transmission line to measurement circuitry, the method comprising:

applying a first AC signal having a frequency ω1 to the transmission line and measuring a first input impedance of the transmission line;
applying a second AC signal having a frequency ω2 to the transmission line and measuring a second input impedance of the transmission line, wherein the frequency ω2 is different than the frequency ω1;
applying a third AC signal having a frequency ω to the transmission line and measuring a third input impedance of the transmission line, wherein the frequency ω is different than the frequency ω1 and different than the frequency ω2;
processing the first input impedance and the second input impedance to measure a ratio:
S
⁡
(
ω
)
=
[
S
⁡
(
ω
⁢
⁢
1
)
S
⁡
(
ω
⁢
⁢
2
)
]
p
⁢
⁢
where
⁢
⁢
p
=
√
(
2
+
4
⁢
n
)
(
1
+
4
⁢
n
-
3
+
4
⁢
n
)
S(ω1) represents an attenuation factor of the transmission line at the frequency ω1, S(ω2) represents an attenuation factor of the transmission line at the frequency ω2, S(ω) represents an attenuation factor of the transmission line at the frequency ω, and n is an integer;
and
measuring a resistance of the load based on and the measured third input impedance and the attenuation factor S(ω).

57 more elements

Dependencies are inferred from the claim text.

Measuring a load resistance coupled to a transmission line

Life of this patent

Measuring a load resistance coupled to a transmission line

Life of this patent

Abstract

Claims19