antenna-theory.com
Antenna Theory

 Search found 197 matches
Author Message
Topic: Reduce chance of TVI

Replies: 1
Views: 13

Forum: Questions Related to Antenna Theory   Posted: Sun Mar 18, 2018 3:26 am   Subject: Reduce chance of TVI
I don't think it should matter, those antennas pointed at your garden are receive only antennas
Topic: antenna Q factor is low

Replies: 2
Views: 254

Forum: Questions Related to Antenna Theory   Posted: Tue Mar 06, 2018 8:55 pm   Subject: antenna Q factor is low
If your Q is low, you need to find the loss or maximize inductance

tightly couple your loops, improves your inductance faster than the resistance goes up
if you are backed by metal, you need ferri ...
Topic: Far field in arrays

Replies: 4
Views: 994

Forum: Questions Related to Antenna Theory   Posted: Wed Dec 27, 2017 11:46 pm   Subject: Far field in arrays
You didn't ask if it is impossible to use an array under the far field distance, you asked what conditions are required such that the far field approximations are accurate
Topic: Far field in arrays

Replies: 4
Views: 994

Forum: Questions Related to Antenna Theory   Posted: Wed Dec 27, 2017 5:22 pm   Subject: Far field in arrays
The entire array. If you have a large array and aren't far away relative to the size of the array then the angle of arrival for each antenna will be different, so you can't use the traditional beamst ...

Replies: 1
Views: 921

Forum: Questions Related to Antenna Theory   Posted: Mon Nov 27, 2017 9:53 pm   Subject: How can you disable antenna that the Xbox One controller use
Yes, you found the antenna. Looks to me to be a modified pifa antenna, a bit different than an IFA, but they are somewhat similar anyway: http://www.antenna-theory.com/antennas/patches/pifa.php

...

Replies: 3
Views: 2002

Forum: Questions Related to Antenna Theory   Posted: Mon Sep 25, 2017 5:07 pm   Subject: RFID Antenna complex impedance calculation
Makes no sense. Measure the antenna with a single port and you can get the impedance directly.

Replies: 3
Views: 2002

Forum: Questions Related to Antenna Theory   Posted: Fri Sep 22, 2017 5:32 pm   Subject: RFID Antenna complex impedance calculation
First question: Why are there 2 ports in your measurement? Antenna is a 1 port device.

Replies: 3
Views: 2155

Forum: Questions Related to Antenna Theory   Posted: Tue Sep 19, 2017 9:25 pm   Subject: Artifact: is it an antenna?
Yeah that is a PIFA antenna [http://www.antenna-theory.com/antennas/patches/pifa.php]

Basically, the lowest frequency of operation is about a quarter wavelength for the length of the arm. The arm ...

Replies: 3
Views: 2155

Forum: Questions Related to Antenna Theory   Posted: Mon Sep 18, 2017 6:17 pm   Subject: Artifact: is it an antenna?
That does look like an IFA or PIFA antenna, modified for some reason (additional bandwidth? lower operating frequency?) From the size, I'd estimate somewhere in the 75-300Mhz region.

The back si ...

Replies: 2
Views: 1989

Forum: Questions Related to Antenna Theory   Posted: Tue Aug 29, 2017 5:13 pm   Subject: Problems in plotting figure 5 in the course antenna theory
Looks like your taking cosine of an angle in degrees, should be radians

Replies: 0
Views: 2355

Forum: News   Posted: Fri Jun 09, 2017 9:17 pm   Subject: Antenna Theory.com Releases a VNA
Hi Everyone,

I've developed a 400MHz-2.7GHz VNA, with the application being focused towards consumer electronics frequency bands (cellular, gps, wifi, bt, etc).

It is available now on kickstarte ...

Replies: 2
Views: 2878

Forum: Questions Related to Antenna Theory   Posted: Fri Jun 09, 2017 9:16 pm   Subject: Radiation from coax antenna cable
Great Question.

So imagine you have a dipole antenna that is small, say a quarter wavelength (so 31mm at 2.4GHz or whatever). If I want to measure this antenna, I put a coaxial cable up to it with ...
Topic: Three antenna Device

Replies: 2
Views: 2771

Forum: Questions Related to Antenna Theory   Posted: Mon Apr 24, 2017 6:02 am   Subject: Three antenna Device
Antennas are not perfect filters in that they receive only one frequency.

If you have a small antenna (let's say resonant at 5.8GHz), it may have an efficiency of -1 dB (or a gain of + 2 dB). At 9 ...

Replies: 1
Views: 2760

Forum: Questions Related to Antenna Theory   Posted: Thu Mar 30, 2017 9:29 pm   Subject: Quarter Wave Length Whip Capacitance Formula
Haven't seen that formula so can't vouch for it.

You can put an inductor in shunt or series actually to cancel out the reactance. If you use series your impedance will end up very low (1 ohm), if ...

Replies: 3
Views: 3681

Forum: Questions Related to Antenna Theory   Posted: Mon Feb 20, 2017 7:21 pm   Subject: Friis Transmission Equation Frequency Dependence Question
Yes that referenced article is correct.

A more complete statement for pathloss is that "for fixed gain antennas, the pathloss increases with frequency". But you could also say "for ...

 Page 1 of 14 Goto page 1, 2, 3 ... 12, 13, 14  NextAll times are GMT
 Jump to: Select a forum The Antenna Forum----------------Questions Related to Antenna TheoryNews