Microstrip or coplanar waveguide?

Hi all,

I am designing a multiple stopband filter using split ring resonator.I have read a lot of papers for stop band filter using both transmission line.I am rather confused which one should i use? Because both also have a lot of application in stop band filter.

Anyone have idea?Thanks in advance.

Regards,
Chai Ling

Hello,

the answer may depend on many parameters: Available technology, frequency range, impedances. For low impedance, e. g. 50 ohms, I would expect microstrip to offer lower losses.

Regards,
Frank

MIcrostrip is open in one side, is dispersive and creates modes.
No apropiated for internal layers.
Stripline is almost the same than microstrip but does
have double ground plane which allow it to be embedded. It
is almost TEM. Less dispersive than microstrip, important
for very high frequencies.
CPW is the mirror(complementary) of the stripline. Create
differential modes that maybe creates leakeage. The size of the
separation between traces tend to be small, then needing low
dielectric.

Add the issues of vias and connector interfaces to your thinking as well. That may shade your choice based on your particular application.

CPW lenes have an advantage when it comes to shunt elements as there is a easily accessablle groundplane nearby (on the same side of the PCB). Microstrip has the driven conductor on one side of the dielectric and the groundplane on the other.

There is no really clear answer that I am aware of. CPW lines are more complicated but I would expect better shielding, particularly where side and lower groundplanes (and via stitching) are in the mix.

Why would a CPW line have more loss (s21) than a microstrip?

HI all,

Thanks for ur reply.

The resonant frequency i want from split ring resonator(circular and rectangular) is 2.45GHz,5.2GHz,5.8GHz(ISM frequency).

FRom the paper i read, usually 4 rings are used to get a high frequency selective and sharp cutoff.So i think of i should have 3 "line" of split ring resonator(SRR).

Hi,
you can use spilt ring resonator,in fact i have designed and tested .If you use one or two section the insertion loss will be less than 1 dB.
Here, the harmonic supression is better than to coupled line filter aslo.
Other thing, you can see some papers where you can use tune the resonance frequency by putting capacitor between two sections.
Regards,
Bibhu

HI Bibhu166,

U have designed split ring resonator before?and u know how 2 calculate the resonant frequency?

May i contact u if i have any problems?

Thanks a lot.

Regards,
Chai Ling

Hello

I am new user to RF designing . If I am given H & T of subtrate how can I compute W?

Use APPCAD, you can find it here:
http://www.hp.woodshot.com/