Welcome to WIFI Antennas

Register now to gain access to all of our features. Once registered and logged in, you will be able to contribute to this site by submitting your own content or replying to existing content. You'll be able to customize your profile, receive reputation points as a reward for submitting content, while also communicating with other members via your own private inbox, plus much more! This message will be removed once you have signed in.

swarg_eu

DVB-T2 Front End

35 posts in this topic
On 10/26/2020 at 2:19 PM, swarg_eu said:

for this type of antenna, a simple power splitter is not a solution (no phase shift between ports)

the patches need to be driven with a 180 deg phase shift, otherwise, there will be no main lobe in the radiation pattern (in its place will be a zero)

Therefore it uses a transformer (wire loop) that transforms the single-ended (asymmetric) to differential (symmetric, 180 deg phase shift) port

the rest of the PCB traces (GND below) ensures a proper impedance match 

on this kind of FEED , phase and z adapters...(pretty sure there some ...at least 3db) Not counting dielectric losses...just the splitters....

Share this post


Link to post
Share on other sites

it depends on how you look on the splitter/combiner 

- splitter, 2 output  ports with a 3dB "loose" compared to the input 

- combiner the output has a 3dB "gain" compared to the 2 input ports (assuming the phase and amplitude match)

the question is actually what you do with the splitted/combined signal 

 

in the case of an antenna, the feeding network for the patches splits the power while TX and combines the power while RX

the TX antenna gain and the radiation pattern is a result of the superposition (amplitude and phase) of the patches radiation 

the RX antenna gain and pattern are the results of the combined patch (pattern) signals (amplitude and phase) 

 

in the case of a passive antenna, the feeding network is the same for TX & RX resulting in the same pattern for TX & RX and doubling the patch count increases the antenna gain by 3dB (combiner/slpitter)

2 people like this

Share this post


Link to post
Share on other sites
11 minutes ago, Admin said:

swarg_eu,You can design such a divider...???

screenshot_2160.jpg

that not a problem,

 

but depending on the frequency a 90 deg hybrid or a ratrace is a better solution  

Share this post


Link to post
Share on other sites

1400 MHz-2600 MHz, broadband circularly polarized microstrip antenna with two gap-coupled probe feeds;

 

Dimensions ..

2160.jpg

Share this post


Link to post
Share on other sites
On 8/13/2020 at 9:52 PM, swarg_eu said:

Combined via 3 x wilkinson splitter

2x antenna on wilkinson

2x wilkinson on wilkinson 

Its just added 6dBi gain by combining the 4 antennas to a 2x2 array

 

What software fo you use for Fresnell zone calc ?

Share this post


Link to post
Share on other sites

Simogyi FZ56 advertised as 56 dB gain DVT-T2 HEVC antenna - with 199,99 HRK pricing.

How does that compete with 4 x phased-array 4 x Iskra + your Wilkinson switch and what would be the pricing for your switch ?

Additional question :
Since we loose 1 dB for every F-conenctor, can a version with screw on cable be produced to sqeeze extra 5 dB out of your system ?
 

Sincerely,

Josip

14215_1_03_01_Page_1.jpg

14215_1_03_01_Page_2.jpg

14215_1_03_01_Page_3.jpg

14215_1_03_01_Page_4.jpg

Share this post


Link to post
Share on other sites

Jossip,if I understand you want something like that....

screenshot_1251.jpg

Share this post


Link to post
Share on other sites

There are 2:1 4:1 combiner, filer, LNA separately and the 4:1 filer and LNA on single board  

IMG-5836f71d12c1305834f6e51c0cd03fbd-V.jpg

1 person likes this

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now