Welcome to EDAboard.com

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.

how to increase printed yagi antenna's gain?

Status
Not open for further replies.

tv60s

Newbie level 5
Joined
Apr 27, 2007
Messages
8
Helped
1
Reputation
2
Reaction score
1
Trophy points
1,283
Activity points
1,343
yagi antenna gain

Could someone help and suggest on what i could do to increase my printed yagi antenna's gain? At the moment, i could only achieve a gain of about 3dB.Im trying to design a printed yagi antenna with gain of around 10dB.The antenna operating frequency is 2.4GHz and im using FR4 as the substrate.Could someone help me?
 

man_arief

Member level 3
Joined
Mar 20, 2006
Messages
58
Helped
6
Reputation
12
Reaction score
2
Trophy points
1,288
Activity points
1,585
lawson yagi antenna design

If someone can achieve 10 dB gain in printed antenna, I am also want to know....
 

Azulykit

Advanced Member level 4
Joined
Feb 18, 2007
Messages
1,121
Helped
219
Reputation
436
Reaction score
112
Trophy points
1,343
Location
All over the Map.
Activity points
8,407
yagi fr4

Yagi's can easily achieve gains in the 12 to 15 dBi range. There are numerous examples in the literature and lot's of books on the subject.

Look into the ARRL handbook. HAMS (amateur radio operators) often use this as a reference. w*w.arrl.org is their site. The 20th edition has a DOS based program for Yagi design.

You might also look into Yagi Antenna Design by James Lawson.

They are periodically discussed on this forum as well. Did you try the "search" feature?
 

pabloec

Member level 2
Joined
Sep 20, 2007
Messages
49
Helped
9
Reputation
18
Reaction score
3
Trophy points
1,288
Activity points
1,551
printed yagi

i beleive they r talking about printed yagui....radio amateurs often use wire made yagis the difference is clear, wire made yagi elements are cilindrical elements and printed yagui elements are planar ones,
also the dielecric between them are different ones, wire-made yagis one is air, printed ones have a mixture of air and fr4 that has to be taken into account when designing a printed antenna
i would hardly call any printed antenna of any shape a yagi type.
 

Azulykit

Advanced Member level 4
Joined
Feb 18, 2007
Messages
1,121
Helped
219
Reputation
436
Reaction score
112
Trophy points
1,343
Location
All over the Map.
Activity points
8,407
yagi-uda fr4

Take a look at this: h**p://seattlewireless.net/index.cgi/DirectionalYagi


Don't overlook the search feature on this site.
 

pabloec

Member level 2
Joined
Sep 20, 2007
Messages
49
Helped
9
Reputation
18
Reaction score
3
Trophy points
1,288
Activity points
1,551
yagui 24 dbi antenna

im sorry i dont think you get the question, they are talking about PRINTED antenna, the ones built over a PCB, the link you sent has nothing to do with that.

Azulykit said:
Take a look at this: h**p://seattlewireless.net/index.cgi/DirectionalYagi


Don't overlook the search feature on this site.

please read.

Added after 1 hours 13 minutes:

Hi, since i read this post i got interested, so theres the info i has found so far, hope you can find the any use.
 

Azulykit

Advanced Member level 4
Joined
Feb 18, 2007
Messages
1,121
Helped
219
Reputation
436
Reaction score
112
Trophy points
1,343
Location
All over the Map.
Activity points
8,407
yagi flat metal elements

The basic idea in a yagi-uda antenna is that the pattern of a dipole like element may be modified with parasitic elements. Longer elements tend to reflect the energy to the opposite side and shorter elements (directors) narrow the beam. More directors increase the gain. Guidelines for element sizing is available from numerous sources. The other underlying idea is that only one element needs to be driven and the other parts are passive, making construction easier.

The elements themselves may be round or flat. In a PCB antenna the dielectric is primarily a mechanical support for the conductors. It is generally good practice to keep the material thin while just sufficiently strong for the mechanical requirements. I saw one case where the designer cut most of the dielectric material away leaving only enough to support the elements. It is obvious that it will have an electrical effect and needs to be considered. A PCB based structure is relatively easy to fabricate, particularly in the microwave bands.
 

pabloec

Member level 2
Joined
Sep 20, 2007
Messages
49
Helped
9
Reputation
18
Reaction score
3
Trophy points
1,288
Activity points
1,551
yagi flat directors

i think the effect of the substrate isnt just a supporting structure, because the effect of the difference of relative permitivity (air =1aprox fr4=4.4 aprox) enables different wave propagation(not true modes, far more complex wave interactions) and the existance of very localized nonradiative waveguides inside the substrate(between and below the metal elements).

Also the effect of the triple interfase at the lateral edge air-metal-substrate cannot be effectively modeled in terms of a single dielectric with an single effective relative permitivity as it is usually done with microstrip and strip line analysis.
in a regular yagi the space between the elements is made of one dielectric and as the wire is considered to be thin the effect is almost of a geometrical line(zero width) while this is not really true for a copper line cos its width can be comparable to one tenth wavelength.

Proof of that is that the simulations attached on the first message of this thread could not be optimized as simple an wire-made yagi can be.

i agree one should use the thinnest substrate possible, and both models can seem pretty much the same, but they dont work the same, so the same intuitive principles of a wired yagi are not that true for a "pcb yagi".
 

2009kucing

Newbie level 4
Joined
Sep 10, 2009
Messages
7
Helped
0
Reputation
0
Reaction score
0
Trophy points
1,281
Location
indonesia
Activity points
1,315
hai may i ask about yagi dipole with several element dipole and patch yagi uda
can i merge two of diff type antenna above for increase gain ...
 

Status
Not open for further replies.

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Top