wideband L-probe feed, did you hear about?

[mamali]

l probe feed

Dear all interested in wideband microstrip p a tch antennas ,

recently(about 4 years!), a new kind of MPA feeding is used with very interesting charasteristics, as simplicity in manufacturing process, wide bandwidth, ease of impedance matching (although have some trade offs, such as high Xpol in H plane at endfire, or patternn assymetry in higher frequencies of operating band).
bytheway, i think even it is not so recent, but a few heared about, and even used it. i want to announce that it has a really interesting features, suitable candidate for matching narrowband antennas.

looking forward your suggestions and ideas,
your friend,
murti

 

[IICCEE]

wideband l probe microstrip antenna

I think it may use stack type.

 

[mamali]

I think it may use stack type.

Dear IICCEE, what do you mean by "it"? if you mean L-probe feeding, then i should sey that this kind of feed could gains a wide badwidth of roughly 20%~45% with just one p@t ch. and if you mean its better to use a stack patch, then i should sey it could apply to this kind of feed if to separate probe will be used. other wise, matching have a problem
(the stack one could be applicable in two band antennas, it was published, K.F. Lee and others, if you want I can post'em).

ur friend, murti.

 

[Lupin]

I'm involved in a design a probe fed stacked patch antenna at 13 GHz.. anyway, I'ld like to study articles about it as many as I can find..
If u have material, pleasse can u upload it? Thanks.
Anyway a basis doubt is the following:

Probe fed onfiugration can't be used for so high frequencies... is aperture coupling better isn't it?

Best regards
Lupin

 

[caocao]

HI mamali
I upload a paper which talk about "T-Shaped Microstrip-Fed" microstrip patch antenna,and it's bandwidth can achieve about 50%,you can read it.
Regards!
caocao

 

[caocao]

HI mamali
I upload a paper which talk about "T-Shaped Microstrip-Fed" microstrip patch antenna,and it's bandwidth can achieve about 50%,you can read it.Maybe it is likes the "L probe feed".
Regards!
caocao

 

[caocao]

I'm involved in a design a probe fed stacked fix antenna at 13 GHz.. anyway, I'ld like to study articles about it as many as I can find..
If u have material, pleasse can u upload it? Thanks.
Anyway a basis doubt is the following:

Probe fed onfiugration can't be used for so high frequencies... is aperture coupling better isn't it?

Best regards
Lupin

Hi lupin,
The probe fed configuration can be used in high fre such as Ku band,I haved design a 4-elements patch arrays with probe feed at Ku band .It is good !you can test .
regard
caocao

 

[Lupin]

I'm afraid that the performances can be corrupted for a probe-fed configuration at High Frequency cause of Vibration Analysis, dimensions tollerances..
For a Ground Station antenna u don't have this problem but for a satellite antenna it can be a drawback that might affect your antenna performances..

Another thing to say is that the probe might be broken cause of antenna vibrations.. an aperture coupled antenna doesn't have this problem...

What's your feeling?

Regards
Lupin

 

[mamali]

I'm afraid that the performances can be corrupted for a probe-fed configuration at High Frequency cause of Vibration Analysis, dimensions tollerances..
For a Ground Station antenna u don't have this problem but for a satellite antenna it can be a drawback that might affect your antenna performances..

Another thing to say is that the probe might be broken cause of antenna vibrations.. an aperture coupled antenna doesn't have this problem...

What's your feeling?

Regards
Lupin

Dear Lupin, caocao and other friends,
excuse me if i dont see this post for a while, i was a little busy for a paper.
bythe way, i should mention some points.
1. caocao, the paper was about T-shape fed "aperture" antennas, not p@tch antenna.
2. the L-probe is not attached to the p@tch, the probe is bending under the p@tch, and form a L-shaped probe. thus, it has better phisical performance, specially becouse the antenna is not sensitive to probe diameter, and the probe could be made by a thick strong mettal wire.
3.I already use it to miniaturize a fractal p@tch in PCS band for about 75%. the achieved bandwidth is about 15%, surly enough for PCS. it could reach 11% bandwidth of S11<-15dBi too. by the way, this method of feeding has its own drawbacks, as high H-plane endfire crosspol radiation, and pattern assymetry in the upper part of the band. this drawbacks however could be addressed by properly array designs, and other methods. i just wanted to remined people here about this attractive feeding method. yes, aperture coupling is another nice feeding techniquye, but i couldnt use it as a wideband feed for my fractal p@atch.
i will post L-shape probe fed papers here soon.

murti

 

[goxy]

I know for 15-20% bandwith of L-probe feed antenna not so high as you said.
And manufacturing process is not so simple besause you have patch plus L-probe feed. On 2GHz gap is about 3mm, on higher freq gap is smaller.
Also mechanical construction is not stable and besause charasteristic :scrambleup:

RGS

 

[yuen_cityu]

Hi murti,

Thank you for your interest in L-probe fed patch antenna. If Prof. Luk knew someone talking about L-probe, he should be very cheerful. When I left City University of Hong Kong last year, they already found the method to reduce the H plane cross polarization. You had better to search paper if you want to know how to do this.

Regards,
Yuen

 

[mamali]

I know for 15-20% bandwith of L-probe feed antenna not so high as you said.
And manufacturing process is not so simple besause you have fix plus L-probe feed. On 2GHz gap is about 3mm, on higher freq gap is smaller.
Also mechanical construction is not stable and besause charasteristic :scrambleup:

RGS

dear goxy,
this technique could be is used to achieved 42%BW in 4GHz band., more over, this feed is used in MPAs with very thick air gap (10% of lambda0 or more)., so in 2GHz, the airgap is about, say, 17mm, and the probe has a vertical arm of, say, 12mm. and there are a lot of more complicated structures manufactured and used already, for example PIFA.
moreover, the probe could be printed on a substrate and mechanically fixed under the p@tch.

and, i am not the inventor of this kind of feeding, i just want to mention new wideband feeding methods for MPAs. please stop notifying me about its goodness and badness. Its a new technique and under construction! . but shows interesting charasteristics. it has growing applications. u will hear more about it, be sure .

murti

 

[mamali]

Hi murti,

Thank you for your interest in L-probe fed fix antenna. If Prof. Luk knew someone talking about L-probe, he should be very cheerful. When I left City University of Hong Kong last year, they already found the method to reduce the H plane cross polarization. You had better to search paper if you want to know how to do this.

Regards,
Yuen

tnx yuen,
i already have all papers about L-probe fed, and i think recently nothing published about canceling H plane crosspol radiation. i already know they cancel it with array., it is practical. however, it was published in 2000. if you know something new, please inform me, its very important for me.
and, good for you to know Luk. you may also know Lee (Kaifeng). they are great peoples.

ur friend, murti

 

[abdoeng]

hi are u mamali hear about quasi yagi antenna it has wide bandwidth,high cross pol.,and simple in design and small size!!!!!!!!!!!!!!!

 

[goxy]

Hello mamali !

Gap beetwen L-probe and patch radiating element is about 3mm on 2GHz, of course not between radiating patch element and ground plane

I hope will hear more about very soon :wink:

BTW. We can see you are very good inform about this antenna type so please notify us whan you get any news.

 

[plasma]

Hi mamali

for improving the cross pol just print sheet of parallel wires and put it
above your antenna

I think that you can get a high cross pol -35db. low sidelobe -30db
very broadband and very good VSWR.and same beamwidth in E and H plane if you use scalar horn antenna.

RGZ

 

[divan]

2 plasma

really ?!
who tried this ?

 

[mamali]

Hi mamali

for improving the cross pol just print sheet of parallel wires and put it
above your antenna

I think that you can get a high cross pol -35db. low sidelobe -30db
very broadband and very good VSWR.and same beamwidth in E and H plane if you use scalar horn antenna.

RGZ

dear plasma,
thats seems interesting, but the paper u already uploaded is about horn antenna . if you have something published about the method u sed please upload it here, i couldnt find in IEEEXPLORE.
rgrds, murti

 

[caocao]

I'm afraid that the performances can be corrupted for a probe-fed configuration at High Frequency cause of Vibration Analysis, dimensions tollerances..
For a Ground Station antenna u don't have this problem but for a satellite antenna it can be a drawback that might affect your antenna performances..

Another thing to say is that the probe might be broken cause of antenna vibrations.. an aperture coupled antenna doesn't have this problem...

What's your feeling?

Regards
Lupin

Hi lupin
The microstrip patch i talked about is used for Launch Vehicle,I had finished the vibration ,transportation,low air pressure and temperature cycle examination,it's performance is as good as it before testing,such the VSWR is 1.3,after vibration it is 1.4.......
I think the probe feed is good method.
regards
Caocao

 

[Lupin]

Ok caocao,
I think I can begin to work with the probe-fed patch.I never tried the probe at that band..
Another thing, do u have articles about stacked patch antennas? I'ld need to enlarge my library...

Thanks in advance
Lupin