Protecting transmitter PA stages from reflected power and inter-system intermod
A failed antenna, a wet feedline connector, or a strong nearby transmitter can drive reflected power back into the PA — and at multi-carrier sites, two transmitters mixing in a non-linear element generate intermod products that fall back into your receiver band.
The two failure modes
Reflected power: SWR climbs above 2:1 and the PA's reverse-power protection trips, or worse, fails open. A ferrite isolator absorbs reflected power into a load, decoupling the PA from antenna-side faults.
Inter-system intermod: when a strong second carrier reaches your transmitter's output stage, the non-linearity generates IM products that fall in-band at nearby receivers. The isolator presents > 75 dB of reverse isolation, suppressing the second carrier before it reaches your PA.
Recommended product
For UHF systems, UHF Dual Ferrite Isolator. For VHF, VHF Dual Ferrite Isolator. For airband, Airband Dual Ferrite Isolator. All three share the same dual-stage construction and temperature-stability curve — pick by band.
Recommended products
UHF Dual Ferrite Isolator
380-470 MHz, > 75 dB typical isolation @ +25 °C, 150 W, < 1.0 dB IL, 1.5:1 VSWR.
- Freq
- 380–470 MHz
- Power
- 15 W
- Isolation
- > 75 dB
VHF Dual Ferrite Isolator
145-175 MHz, > 75 dB typical isolation @ +25 °C, 150 W, < 1.0 dB IL, 1.5:1 VSWR.
- Freq
- 145–175 MHz
- Power
- 15 W
- Isolation
- > 75 dB
Airband Dual Ferrite Isolator
112-137 MHz, > 75 dB typical isolation @ +25 °C, 150 W, < 1.0 dB IL, 1.5:1 VSWR.
- Freq
- 112–137 MHz
- Power
- 15 W
- Isolation
- > 75 dB
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