When a signal path has to route cleanly at RF, the part you pick decides whether the bench behaves or drifts. Two families cover most of that work: Teledyne coaxial switches and Teledyne relays. They read as one line item on a datasheet, yet they solve different problems, and specifying the wrong one shows up later as repeatability faults, insertion loss you did not budget for, or a switch that wears out mid-run.
This guide sets the two side by side on the numbers that matter to a working engineer: switching life, insertion loss, isolation, and the configurations that suit a given system. Whether you build ATE racks, integrate RF subsystems, or keep a fleet of instruments serviceable, the aim is the same: match the part to the duty cycle and frequency in front of you.
Key Takeaways
An RF relay is an electromechanical device that opens and closes a signal path, usually compact and board or panel mountable, built for moderate switching rates and mid frequencies. A coaxial switch is a precision mechanical assembly with a controlled-impedance path, actuator driven, and rated to far higher frequencies with tighter isolation.
Put simply:
Teledyne builds both under one roof, so you can compare like for like rather than mixing vendors across a signal chain. The full range and the case for each part sits in Teledyne relays and coaxial switches.
Life rating is where the two families part company. A coaxial switch is designed for millions of actuations with stable contact resistance, which matters when a single ATE sequence cycles a switch thousands of times a shift. An RF relay carries a lower life rating, fine for occasional path changes, less so for a high-duty automated bench.
Before you specify, work out the real cycle count per day, not the nameplate maximum. A part rated well above your duty gives predictable life; a part run near its limit becomes the thing that fails first.
Ask us to review your duty cycle
Two figures decide RF behaviour. Insertion loss is the signal you lose through the closed path; isolation is how well an open port rejects leakage. Coaxial switches hold both tighter and hold them higher up the band, into the tens of GHz, with flat performance you can trust across a sweep. Teledyne relays perform well at lower frequencies and loosen off as you climb.
For a calibrated measurement, low and repeatable insertion loss matters more than a single headline number. A switch whose loss shifts between actuations quietly corrupts your uncertainty budget.
Configuration is the practical filter. Map the switch to the job:
Confirm frequency range, connector type, actuator voltage, and whether you need latching or failsafe behaviour before you raise the order. A wider view of where each part fits sits in our guide to RF and microwave components.
Browse Teledyne relays and coaxial switches
Counterfeit and relabelled RF parts circulate, and a fake switch fails every spec above at once. Buy through an authorised channel, check date and lot codes against the part number, and treat pricing that looks too good as a warning. Our walkthrough on how to spot counterfeit RF components covers the checks that protect your build.
Not sure which family your system needs? Talk to the Emerges team about the right Teledyne part and we will match switching life, loss, and isolation to your spec.
What is the difference between a coaxial switch and an RF relay?
A coaxial switch is a precision, actuator-driven assembly with a controlled-impedance path, rated for higher frequencies, tighter isolation, and millions of cycles. An RF relay is a more compact electromechanical device suited to board-level routing at moderate rates and mid frequencies.
How do I compare switching life across Teledyne parts?
Read the rated actuation count on each datasheet, then weigh it against your real duty cycle per day. Coaxial switches carry far higher life ratings than RF relays, so a high-duty ATE bench should specify a switch rated well above its expected cycles.
What insertion loss and isolation should I expect?
It depends on frequency and configuration. Coaxial switches hold low insertion loss and high isolation into the tens of GHz with flat, repeatable behaviour. RF relays perform well at lower frequencies and loosen as frequency climbs. Always read the figures at your operating band.
Which configuration suits test and measurement systems?
Benches usually want SPDT or transfer switches for clean A/B paths, while ATE racks lean on SP4T, SP6T, or matrix blocks with high cycle life. Confirm connector series, actuator voltage, and latching versus failsafe behaviour before ordering.
How do I confirm I am buying genuine Teledyne parts?
Buy through an authorised distributor, check date and lot codes against the part number, and be wary of pricing well below market. Our guide on spotting counterfeit RF components lists the checks to run.