I am very new to EM, i would like to design a uslot patch antenna for the centre frequencies 3.65GHz and 5.25GHz in CST Microwave studio.
I have looked through journals and they dont explicitly state the equations used. The main equations i see are the ones related to the patch antenna design only.
Any and all help will be appreciated.
https://imgur.com/a/g8z3a4R
Sorry for formatting, mobile.
I went for the annual service two days ago. After that i parked my car into an unknown part of the city and then I went home. Tonight i noticed this thing mounted on the roof antenna slot. It is 1 inch long and it has some grease or oil on the part which gets screwed in. I removed it quite easily/normally. I don't keep my antenna mounted, so it wasn't stolen, just this thing got mounted.
Is it something that the dealership mechanics put in and the forgot to take off? Is it a prank? Or is it a tracking device and i should be worried?
Hi everyone:
Just wanted to share an antenna project I am working on. The concept is a near-ground (1/2 meter off the ground), vertically-polarized skeleton slot antenna. The intent of this antenna is an emergency antenna or for Field Day in places (like a beach or parking lot) where trees or other vertical supports are not available.
The antenna is made using six five foot pieces of 1/2 inch copper pipe, with four of them being screwed or coupled together mechanically to make 10 foot (3.3 meters) lengths; and the other two being connected with a wooden dowel and a CPVC coupler (to make an insulated feed point). The three 10 ft copper pipe sections are mounted vertically (I am setting them on 1/2 inch wooden dowels sunk in quick-setting concrete in plastic buckets). And then along the top and bottom of the copper pipes, I'm running some 16 gauge speaker wire. The two copper pipes on the ends are about 30 feet (9.5 meters) apart but the distance is not critical. The antenna is fed with 300-ohm twin-lead and requires an antenna tuner (although with a 4:1 balun it resonates close to 15 meters / 21 MHz).
The result is basically the same as G3VCG's skeleton slot antenna for HF but flipped 90 degrees. The antenna polarization should be vertical, even though it is longer than it is tall.
This should work "OK" on 20 meters through 10 meters, and can "sort of work" on 40 meters and 30 meters also. I haven't tried it on 80 but I assume that is just sheer insanity. On 6 meters, the pattern breaks down as it would with a dipole, into multiple lobes.
The advantages of this design:
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Should allow you a dipole-like pattern without needing it to be very high off of the ground. In fact, you could make this into a "yagi" by putting a quarter-wave monopole (with radials) 1/4 wave or so behind it. Otherwise, it has a bidirectional pattern. At higher frequencies (28 MHz) the lobes should be pretty tight and be competitive with a two-element yagi in terms of gain (though with no front-back gain). You can rotate the pattern by just moving the buckets around on the ground. Not as elegant as a yagi with a rotor but simple enough especially if you have kids hihi.
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The elevation angle should be relatively low, sort of like a ground-mounted vertical antenna.
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By unscrewing the copper poles this antenna breaks down into a package small enough to throw into the back seat of a car (if you used something less clunky than the concrete-filled buckets you could probably
(I come from r/amateurradio) I have read that single-sided slotted waveguide antennae are omnidirectional. However, their radiation backwards is highly attenuated (not uniform wrt phi). In the other hand, double-sided slot antennae hace two series at +-90°. I have algo heard about Alford slot antennae, but they have not a lot of gain.
Which one fits the best the needs of a microwave beacon?
Thank you in advance
I’ve read some articles on how to use an old satellite dish on your roof into a stealth slot antenna. I live in an HOA and already have one of these up oh my roof so this would work great. My question is: could I make this dual band? For both 2m and 70cm? Two different slots running into a coaxial splitter into the main coaxial into my house connected to my radio? Forgive me if this doesn’t work with physics. I’m a new ham.
Hi! I'm in the market for a better phone. I'm currently on the Samsung Galaxy A01, and now I have some money to spend on one that does more what I need. I live pretty remotely and the hills block what little signal there is. I got a cell signal booster and I'm still not able to make phone calls reliably (though I'm browsing reddit with it right now at a couple bars of 4glte). I'd like the best internal antenna I can get for under $1000, or if possible under like $750. I understand it might just be a moot point, but I have some extra money to spend on it so why not get the best signal possible right? I landed on the galaxy a80 because of some list I found. Then I looked a little further and found a Huawei Mate 20 pro. I don't know what I'm doing really soooo...
Can anybody say which phone they would get? My hard criteria: very good internal antenna, accepts a micro SD card, decent battery life, unlocked or Verizon compatible... all cameras these days surpass my expectation, and most phones have plenty computing power for what I do.
Thanks in advance, hope the wall of text isn't terrible!
[Article]
Title: Compact notch slot antenna with quasi-isotropic radiation for UHF RFID tags
Author(s): Dai, Qingfeng · Yu, Yufeng · Zhang, Shuai · Li, Hui
In: 2016 IEEE 5th Asia-Pacific Conference on Antennas and Propagation (APCAP), 2016-7, p. 71–72
DOI: 10.1109/APCAP.2016.7843104
URL: https://ieeexplore.ieee.org/document/7843104
Thank you in advance!
