Measurement system for analysing radio frequency signals, and method of operating the same

Patent metadata

Field	Value
Publication number	US-12332290-B2
Application number	US-202217949774-A
Country	US
Kind code	B2
Filing date	Sep 21, 2022
Priority date	Oct 26, 2021
Publication date	Jun 17, 2025
Grant date	Jun 17, 2025

Abstract

Disclosed is a measurement system for analysing RF signals. The measurement system includes an optically transparent enclosure including an optically pumpable gas, and a printed circuit board, PCB including an electrical transmission line for guiding the RF signal to be analyzed through the enclosure and a reflective planar face. The measurement system includes an optical pump for emitting preferably coherent light onto the reflective planar face, and a detector for detecting an optical property of the emitted light being reflected by the reflective planar face. This provides a better laser/microwave overlap in atomic vapor quantum sensing setups, where it is crucial to overlap the regions with highest laser intensity and microwave field strength.

First claim

The invention claimed is:

1. A measurement system for analysing RF signals, comprising
an optically transparent enclosure comprising an optically pumpable gas;
a printed circuit board, PCB, comprising an electrical transmission line for guiding the RF signal to be analyzed through the enclosure and a reflective planar face;
an optical pump for emitting preferably coherent light onto the reflective planar face; and
a detector for detecting an optical property of the emitted light being reflected by the reflective planar face.

2. The measurement system of claim 1 ,
the gas comprising an alkali metal, preferably Rubidium.

3. The measurement system of claim 1 ,
the transmission line comprising an insulator layer sandwiched between conductor layers.

4. The measurement system of claim 3 ,
the transmission line including one of:
a microstrip; and
a coplanar waveguide with ground.

5. The measurement system of claim 1 ,
the PCB including one of:
a reflective coating; and
a polished conductor layer.

6. The measurement system of claim 5 ,
the reflective coating comprising one of:
a reflective dielectric coating comprising a quarterwave stack of alternating high and low index layers; and
a reflective metal coating.

7. The measurement system of claim 1 ,
the reflective planar face of the PCB having a reflectance for the emitted light in excess of 80%.

8. The measurement system of claim 1 ,
the emitted light having a wavelength in accordance with an energy transition of the gas, preferably 780 nm or 795 nm.

9. The measurement system of claim 1 ,
the optical pump arranged to emit the light in a continuous wave, CW, mode or in a pulsed mode.

10. The measurement system of claim 1 ,
the optical pump arranged to emit the light perpendicularly to a propagation direction of the RF signal.

11. The measurement system of claim 1 ,
propagation directions of the emitted light and the reflected light forming an intermediate angle of at most 174°, preferably at most 160°, more preferably at most 140°, and most preferably 90°.

12. The measurement system of claim 11 ,
the detector and the optical pump arranged non-coaxially in accordance with the intermediate angle.

13. The measurement system of claim 1 ,
the detector comprising one of:
a photodiode; and
a camera.

14. The measurement system of claim 1 ,
the PCB comprising two electrical transmission lines on respective reflective planar faces of the PCB; and
the measurement system comprising
two optical pumps for emitting light in accordance with an energy transition of the gas; and
two detectors for detecting an optical property of the emitted light emitted by the respective optical pump and reflected by the respective reflective planar face.

15. A method of operating a measurement system for analysing RF signals,
the measurement system comprising
a optically transparent enclosure comprising an optically pumpable gas;
a printed circuit board, PCB, comprising an electrical transmission line and a reflective planar face;
an optical pump; and
a detector;
the method comprising
guiding the RF signal to be analyzed through the enclosure via the transmission line;
emitting coherent light onto the reflective planar face; and
detecting an optical property of the emitted light being reflected by the reflective planar face.

Assignees

• Rohde & Schwarz

Inventors

• Ruster Thomas
• Bueno Diez Miguel

Classifications

• G01R1/24

  Transmission-line, e.g. waveguide, measuring sections, e.g. slotted section · CPC title

• G01R33/26

  using optical pumping · CPC title

• G01R33/032

  using magneto-optic devices, e.g. Faraday {or Cotton-Mouton effect} · CPC title

• G01R29/0885 Primary

  using optical probes, e.g. electro-optical, luminescent, glow discharge, or optical interferometers · CPC title