Ku-band antenna for a handheld spectrum analyzer

[kylecsmith2]

I purchased one of Agilent's handheld spec - A's for field use, but they wanted to charge a ton for antennas. In my overconfidence, I decided I would find antennas from a third party. 3 weeks later, I still have not found what I am looking for. My biggest issue is my Ku-band requirement. Does anyone know where I can find an antenna that meets the following:

form factor: small (I envision less than 18" long), omni,
connector: n-type
frequency: 12 - 18GHz

link to the spec A:
N9344C Handheld Spectrum Analyzer (HSA), 20 GHz | Agilent

I am a mechanical engineer titled systems engineer and now dabbling in RF/electrical engineering, so this is new territory for me. Bare with my ignorance.

Thanks

 

[prcguy]

Check Ebay for small log periodics from Tecom, AEL, WJ and others. You can find them from about 10 to 18GHz and they can go for $100 on up used, usually mil surplus. There is also the occasional standard gain horn that covers 12-18GHz and they can go for about the same price on Ebay.

Pasternack has some of the cheapest prices on new standard gain horns with generic textbook cal tables. I bought one of their Ku horns and had it run through a cal lab at a later date. I also bought C and Ka horns from someone else but I'll have to check the mfr when I get to work today.

What are you measuring at Ku?
prcguy

I purchased one of Agilent's handheld spec - A's for field use, but they wanted to charge a ton for antennas. In my overconfidence, I decided I would find antennas from a third party. 3 weeks later, I still have not found what I am looking for. My biggest issue is my Ku-band requirement. Does anyone know where I can find an antenna that meets the following:

form factor: small (I envision less than 18" long), omni,
connector: n-type
frequency: 12 - 18GHz

link to the spec A:
N9344C Handheld Spectrum Analyzer (HSA), 20 GHz | Agilent

I am a mechanical engineer titled systems engineer and now dabbling in RF/electrical engineering, so this is new territory for me. Bare with my ignorance.

Thanks

 

[kylecsmith2]

both log periodic and horn look cumbersome for field use. Is there a functional reason why you suggest these? I had Antcom quote me a vertically polarized omni with a 3 in gooseneck, which (if I interpreted correctly) is a far more manageable form factor: long-slender-cylindrical.

measuring/detecting digital video and telemetry.

 

[kylecsmith2]

Any input on this?

 

[prcguy]

I can't say I've seen an omni antenna used on a spectrum analyzer for microwave frequencies and log periodics, horns or other directional types are common. Usually you are looking for the source of interference or making measurements where you want to minimize reflections, etc that may skew the measurement.
prcguy

Any input on this?

 

[mmckenna]

I have a 9342C analyzer at work, same as yours, only goes to 7 gig though. I use an Aaronia HyperLog 7060. www.aaronia.com
Can't remember what I paid for it, but it was under $1000.

Not sure I've ever seen a vertical that will go that high. Might have to make your own.

 

[zz0468]

A waveguide slot antenna can make an effective omnidirectional antenna at that frequency range, although I am skeptical that one antenna can be made to cover the entire frequency band of interest. They are essentially the waveguide equivalent of a collinear antenna, and gain and pattern characteristics will change with frequency. A slot antenna is much more narrow banded than the waveguide pass frequencies.

WR62 is a WG size that works from around 12 to 18 GHz. A slot antenna made from that would probably have a bandwidth of less than 1 GHz... probably much less.

There are things like this out there:

Antenna Omnidirectional 11 70 12 75 GHz V H KU Band for TV Distribution | eBay

Note the price, and the restricted bandwidth.

As previously discussed, I would use a horn antenna. Start looking here:

WR062 12.4 GHz to 18.0 GHz Standard Gain Horns

 

[kylecsmith2]

thanks for the help. Thats a little rich for my blood. were looking for a low cost solution. I found an omni Ku antenna with an internal LNA laying around. I'm going to attempt to use that. i just need to find the right bias tee and small power supply to power it.

Again thanks everyone for the help. if you have any recommendation for cheap bias tee purchasing sources i am all ears.

 

[zz0468]

thanks for the help. Thats a little rich for my blood. were looking for a low cost solution.

When you're talking about microwave components, there really isn't such a thing as a low cost solution unless you can engineer and build it yourself.

I found an omni Ku antenna with an internal LNA laying around. I'm going to attempt to use that. i just need to find the right bias tee and small power supply to power it.

I'm curious as to what that might be.

I'm at a loss to understand what exactly is driving the requirement for an omni-directional antenna at that frequency range. Particularly if an LNA is inserted, measurements will be merely relative measurements, with little chance of any real calibrated measurements taking place.

Again thanks everyone for the help. if you have any recommendation for cheap bias tee purchasing sources i am all ears.

Mini-Circuits. They're on the web. But I doubt that they'll have one that works beyond 12 GHz.