Does the frequency range on an antenna matter for transmit?

Question

I am a radio technician in the military currently deployed. We are having a debate about weither or not the Frequency range of the antenna actually matters. Example. I know if you have an antenna that is labeled 150MHz - 175MHz then that means your best receive will be in that range. But we have been debating and having a hard time finding it with all of our blocked internet sites on wiether or not it matters for the TX.

Please help and please leave some reference if you can.

Answer 1

Interesting thread.

I agree it does matter the length should be optimized to
the wavelength, (if you deal with one particular frequency and know what it is) for the most efficient transfer of transmitted, radiated, or received energy, this is best served at the fundamental frequency, but particularly for reception, you can use harmonic 1/2 wave. 1/4 wave etc,etc.

The thing is, variations will work, reasonably well, like coiled antennas, and work along a broad range of frequencies,
but are not optimal for most.

To summarise,
Matched antenna length to transmitted wavelength is
optimal, anything else although it could work reasonably
well, is actually a compromise. Having said that, and to use an example, the difference in wavelength between say 145mhz, and 147mhz, is negliable, and in practical terms could be ignored.

Convercely the difference between 59.5mhz and
1.2gig is huge, and cannot be ignored.

You get it.

LuvUall Ba-Bye,

Answer 2

A transmitting antenna needs to be a resonant circuit ( eg a 1/4 for Current resonance or 1/2 Wave for voltage resonance)
If the antenna is a little bit too long or too short you will get a 'Standing Wave' at the termination.
We adjust the length using a Standing Wave Ratio meter.
If the SWR is 1.3:1 then you lose half the power from the transmitter and consequently your range is 1/4 of that with a SWR of 1:1

Answer 3

Less difference than on the recieve. For reception you want at least 1/2 wavelength of the lowest freq. in your range. Too long can actually allow partial cancellation of the signal. Not usually a problem though.
For transmit generally longer is better. Because the signal is propagating out from the antenna you don't have to worry so much about phase cancellations, the signal is already out there. There are some exceptions with higher freq.
Edit. Just read Max's answer. I like it.

Answer 4

Yes, it does matter. Furthermore the transmission range and the reception range are the same.