EME249 Relay Kit
The Omron
G2RL-14-DC12 Relay Kit is suitable for switching RF from DC to
at least 500MHz, and has a low loss and better than 15dB return loss
to 450MHz. Due to
the contact rating of the relay, it should easily handle up to 400
Watts on the VHF bands. The relay is ideal for antenna switching,
but the isolation between the contacts should be taken into account
when it is used to switch low noise receive pre-amplifiers. Relay
isolation can be improved for a particular frequency band, by
fitting an SMD inductor across the NO or NC contacts on the bottom
of the board.
The Kit is quite straightforward to construct so no notes are supplied. Care should be taken to make sure that the relay is fully seated into the PC board before soldering it into place. SMA connectors are recommended for the best performance, and need to be soldered on both sides of the board for grounding. Alternatively RG316 coax cable can be used, but good microwave terminations to the board are required. BUY THIS PRODUCT
The picture shows the Basic Kit without optional SMA connectors.
This picture shows the bottom of the PC board and where 1008 size inductors can be fitted to L1 or L2 positions to improve isolation on a particular frequency band.
S21 relay through loss from the common to the normally connected contacts.
S21 relay through loss from the common to the normally connected contacts.
S11 return loss through the relay from the common to normally connected contact terminated into 50ohms.
Picture shows relay isolation when a 1008 4.7uH inductor is used across the normally open contacts for resonance on 50MHz.
Picture shows relay isolation when a 1008 1uH inductor is used across the normally open contacts for resonance on 150MHz.
Picture shows relay isolation when a 1008 100nH inductor is used across the normally open contacts for resonance on 450MHz. Isolation is a bit marginal for use with preamplifiers.
