A Novel Comb Generator for Frequency Phase Transfer

TL;DR

This paper introduces a new millimeter-wave frequency comb generator designed for space VLBI applications, demonstrating its ability to produce phase-coherent signals over multiple octaves for precise delay tracking.

Contribution

The paper presents a novel comb generator based on a microwave phase modulator for space VLBI, with successful testing on astronomical receivers.

Findings

Confirmed phase-coherent operation with astronomical receivers

Produced multi-octave bandwidth comb signals

Validated suitability for space VLBI delay tracking

Abstract

This paper presents the design and testing of a millimeter-wave frequency comb generator developed for the Black Hole Explorer (BHEX) mission, a space Very-Long-Baseline Interferometry (VLBI) mission concept. The heart of BHEX is a dual-band receiver, centered at 90 and 270 GHz. This novel comb generator is based on a microwave phase modulator producing phase-coherent comb signals with multi-octave bandwidth, which will be used to track instrumental delays when injected into the receiver system. The comb generator was tested with astronomical receivers, which confirms its expected operation.