Welcome to our site! EDAboard.com is an international Electronics Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.
https://en.m.wikipedia.org/wiki/Chu%E2%80%93Harrington_limit#:~:text=)%20%E2%80%93%20a%20little%20smaller%20than%201,a%20sphere%20that%20encloses%20it.
Look up Chu limit.
There is plenty online regarding these. Many people use cloverleaf(skew planar wheel) circularly polarised antennas as these are tolerant to misalignment and work well. Sometimes this is coupled with a helical antenna on the GCS for more directionality and longer range.
Normally EM software treats mismatch and gain as separate things. You need to plot 'realized gain' that includes the mismatch.
The asymmetry is caused by the feed line. The left hand edge(slot) of the antenna is shorter than the right hand one. The effect isn't huge, less than 1dB in your case...
The original pdf is presented without any context so it's difficult to understand what points the author is making with those figures.
For GPS L1 c/a (2.046MHz BW) code the GPS signal is below the noise floor(in any resolution bandwidth you care to select)...once it reaches earth...with a low...
You can have a look at my blog post where I can discussed some of the factors that influence vivaldi design. https://hexandflex.com/2017/12/06/making-an-ultra-wideband-antenna-part-2/
That sounds cheap to me. When these compabies do assembly they expect it to be on their pick and place line. They need to stop other production runs. Program up the placements. Load your components and inspect the output. This applies double for 0402
Allpcb are good. Oshpark are popular for hobbiests too and might be easier to use than a Chinese company for your first PCB.
Solder the components by hand with a fine tip iron.
Consider going to 0603 and life will be easier. They are still small at 2.4ghz.
Re: Power from basestation to celphone
There are various empirically derived propagation formula such as Elgi, Hata or Cost-231 etc etc. Its not hard to program them into a spreadsheet. I have a free app on my phone that does it.
As others have said it is not an exact science.
There is a pretty good online calculator that will let you play with different spacings, phasings and feed coefficients. This will give you a opportunity to play with various settings to see the effect on the main lobe and side lobe levels...
This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
By continuing to use this site, you are consenting to our use of cookies.
