Circular polrized path antenna design from a paper

[adnan012]

hi,

i want to implement this antenna in ads 2011. how can i define ground plane in ads as shown in the paper?

What is slot plane in ads momentum and what is its purpose?

 

[SpaceDust]

Go to Substrate settings that are found in either Momentum or EMDS drop down from tool bar. Once there choose create or modify substrate, that opens a new window were u need to define ur substrate layer configuration. Default it will be a closed Ground plane and an Alumina Substrate.

1) change the Ground plane from closed to OPEN and other than alumina define a layer below alumina with the properties of air. (eps =1 , mu=1)
2) define ur main substrate Parameters in parameters alloted to Alumina, U can rename it if u want.
3) Find a Tab in that window named layout layers.
4) From below between ur first and second layer , i.e air and alumina, click and define it as a slot, parallelly, check which layer are u defining for slot like cond or cond2 etc..
5) define another layer between alumina and upper air layer, assign this to be a STRIP and if u have assigned cond for prev step, now change it to some other name els u wont be able to assign strip.
6) Setup ur design in Layout and the structure U make for Lower layer, assign cond to it ( or what u assigned in step 4)
7) layout ur design for upper layer and assign material to be cond2 (or what u assigned in step 5).
8) u can check ur design by generating a 3D model option found in EMDS drop down..!!

Regards.

 

[adnan012]

thanks for reply.

Can you explain grafically? i am using ads 2011.10

 

[SpaceDust]

ADS 2011 have a little different appearance to the one i use..!! So i cant upload any pics to explain but If u have understood my prev post, U should get some idea to work it out !!

- - - Updated - - -

http://edocs.soco.agilent.com/display/ads2011/Defining+Substrates+in+an+EM+Simulation

go to this link and check the sections of strip and slot, ..!!

 

[adnan012]

thanks for reply,
Can i use the method as given in the attached file to implement antenna.

 

[SpaceDust]

Absolutely.. This is what u r looking for right, to make a slot in Ground plane..!! All d Best..!!

 

[adnan012]

Thanks or your reply.

i want to ask another question. Suppose that there is a simple quarter wave monopole with center frequency of 100MHz.
It has a bandwidth of 10 MHz . Is it possible to increase band width by adding high order matching network between the source and antenna feed point.
will antenna radiate at all frequencies?

 

[SpaceDust]

Thats a really Good Question, and I Havent given a thought on it before.. Antenna resonance makes its impedance nearly Real, and below and above it acts capacitively and inductively, not sure, could be vice versa not sure, but if u can make ur matching network complimentary in behavior in terms of capacitive and inductive to that of antenna behavior, then ur Band Width can be increased..!! This is just out of theoretical knowledge i have, but no solid reference to it..!! Hope u got my point..!!

 

[adnan012]

Thanks for reply.

Look at this antenna it is wide band from 30 to 512 MHZ. it is a simple monopole whip. it includes a built in matching network as described in datasheet. From this reference can we say that by utilizing matching network antenna bandwidth can be increased to this range (30 to 512MHZ)

What is the meaning of "monopole whip"?
What does it mean that antenna is made of "special wounded wire" ?. is it a helix type winding? or to save material cost? or to make its diameter large?

 

[SpaceDust]

Its a Monopole antenna and matching is a must as its Radiation resistance would come to some 36.5 ohm, and feed is at 50 ohm in general. Matching networks are also used to increase the Bandwidth of an antenna, U shouldn't find much difficulty to find literature on it from google.

As of ur second question, even though monopole antennas are only quarter wavelength, at Low frequencies their length is yet very large, so may design involve Antenna loading techniques to reduce the size of the antenna, .. This is done by making a spring looking wounding at the base of antenna, which gives inductive loading that gets compensated by the capacitive loading due to length reduction of antenna..!!