Continue to Site

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.

Register Log in

reflector design for a monopole antenna

Status
Not open for further replies.
P

pragash

Advanced Member level 2
Advanced Member level 2
Joined
Jul 4, 2005
Messages
518
Helped
64
Reputation
128
Reaction score
59
Trophy points
1,308
Location
Oakland
Activity points
5,001
im currently designing/optimizing a reflector for a monopole antenna. When I was optimizing the distance of the reflector, at a particular distance, I could see the far-field radiation got chopped off in the middle (place where the reflector is located) but I could see the radiation at both sides of the reflector. what does it indicate?
 

Sort by date Sort by votes
An electronics genius told me about AM 'power' stations that broadcast their signal to a different direction at night, to reach a different (or larger) geographical area.

The transmitting array consists of two or more vertical antennas, separated by a particular distance (hundreds of feet), calculated as a certain fraction of the broadcast wavelength. By varying the strength of transmission at one or the other antenna, it changes the shape and intensity of the lobes reached by the signal.

Perhaps you observed a similar operating principle?
 

Upvote 0 Downvote
I'm trying to find the minimum distance a reflector can work. So far, when I put the reflector at a distance very close, it has no effect. At 5mm from the antenna, it's killing the signal at the location of the reflector.

the 1/4 of the wavelength is 90mm. Any idea if this indication at 5mm can give me any clue for reflector placement?
 

Upvote 0 Downvote
If you have a reflector to chang the antenna radition pattern ,then the performance of the reflector is affected by two aspects,one is the length of the reflector itself,and the other is the distance between the reflector and the antenna.Refering to the Yagi antenna principle,the reflector length is 1/2 of the wavelengeh,and the antenna spacing is 1/4 of the wavelength,and the reflector's reflection ability is maximum.However,in actual use,usually due to space reasons,the spcacing between the reflector and the antenna is not enough,usually we adjust the antenna spcing to 1/8 or 1/16 of the wavelength,but in this case,the reflection performance of the reflector is sacrifficed,but he can still play a reflection role.
 
Upvote 0 Downvote
Will 1/16 of wavelength spacing work? Do you have any example of a 1/16 wavelength spacing reflector antenna? By the way, I brought the reflector away up to 1/22 of wavelength spacing, and it didn't work.
 

Upvote 0 Downvote
I made 2.4GHz antenna before,dipole from plus a reflector,reflector and antenna spcacing is 1/16 wavelength.antenna gain is 5dBi
 
Upvote 0 Downvote
May I ask which type of reflector you use? I'm trying to understand if reflector type has anything to do with 1/16 distance. I have attached popular reflector types here.
Reflector1.png
 

Upvote 0 Downvote
1687617358730.png

Similar to the director diagram in the above picture.above the antenna is a dipole,below the reflector is a reflector.I guess your reflector is not good because of the reflector length,the reflector can reflect the frequcecy is not what you need.
 

Upvote 0 Downvote
Status
Not open for further replies.

Similar threads

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Back
Top