Quadrature Hybrid Construction
 

I need several quadrature hybrids (i.e. a 90 degree two-way splitter)
for use in portions of the 0.5 to 2.0 MHz band. This is for a
low-power phasing scheme. Normally I would obtain them from some place
like Mini-Circuit but some reason they only offer a 1.13 to 1.38 MHz
model (PSCQ-2-1.25). Can anyone suggest a source of supply?

Suppose I could also build them but am not familiar with the
construction techniques used at these low frequencies. Am more
accustomed to stripline and microstrip at VHF and UHF. Any suggestions
here would be appreciated. I am sure the techniques are well known and
must be covered in some articles, books and/or web sites.

Quadrature Hybrid Construction
 

"Radra" wrote in message
ups.com...
I need several quadrature hybrids (i.e. a 90 degree two-way splitter)
for use in portions of the 0.5 to 2.0 MHz band. This is for a
low-power phasing scheme. Normally I would obtain them from some place
like Mini-Circuit but some reason they only offer a 1.13 to 1.38 MHz
model (PSCQ-2-1.25). Can anyone suggest a source of supply?

MCL has them near all the way from DC to visible light.

Suppose I could also build them but am not familiar with the
construction techniques used at these low frequencies. Am more
accustomed to stripline and microstrip at VHF and UHF. Any suggestions
here would be appreciated. I am sure the techniques are well known and
must be covered in some articles, books and/or web sites.

Reed Fisher, "Twisted-wire Quadrature Hybrid Directional Couplers". QST
January 1978. pp 21-23.

W4ZCB

Quadrature Hybrid Construction
 

Radra wrote:
I need several quadrature hybrids (i.e. a 90 degree two-way splitter)
for use in portions of the 0.5 to 2.0 MHz band. This is for a
low-power phasing scheme. Normally I would obtain them from some place
like Mini-Circuit but some reason they only offer a 1.13 to 1.38 MHz
model (PSCQ-2-1.25). Can anyone suggest a source of supply?

Suppose I could also build them but am not familiar with the
construction techniques used at these low frequencies. Am more
accustomed to stripline and microstrip at VHF and UHF. Any suggestions
here would be appreciated. I am sure the techniques are well known and
must be covered in some articles, books and/or web sites.

http://www.seboldt.net/k0jd/phase_notes.html

73, Leon

Quadrature Hybrid Construction
 

The range from .5 to 2 MHz is an extremely broad frequency range to get
90' using any sort of LC network. It is greater than an octave, and that is
why it's a problem. Generally, most phase shifters cover less than 1
octave....

If you are thinking about shifting a Local oscillator signal, I'd
recommend a digital approach.

If you multiply the LO by 4, you can then divide by 4 to get perfect 90'
phase shift.



Jim

Quadrature Hybrid Construction
 

Jim wrote:
The range from .5 to 2 MHz is an extremely broad frequency range to get
90' using any sort of LC network. It is greater than an octave, and that is
why it's a problem. Generally, most phase shifters cover less than 1
octave....

If you are thinking about shifting a Local oscillator signal, I'd
recommend a digital approach.

If you multiply the LO by 4, you can then divide by 4 to get perfect 90'
phase shift.

He wants to cover *portions* of the band using several hybrids.

73, Leon

Quadrature Hybrid Construction
 

I am willing to use several hybrids to cover the band, if I must. But
it would be helpful to use broadband hybrids so I don't need to use so
many. I appreciate the reference to the QST article on hybrid
construction. I will build one to see how much bandwidth I can get.
Would like to find a construction technique which yields wider
bandwidth tho. The PSCQ-2-32 from Mini-Circuits has a 3.2 to 32 MHz
bandwidth! Wonder how they do it.

The LO technique is not applicable for my design but it is interesting.
I will have to give it some thought to understand how it works.

Vinton

Quadrature Hybrid Construction
 

you use the same techniques. you only switch to lumped components!
quite a time ago there was a paper in QST, describing just what you
need, but it's going to take me sometime to track it and rescan it.
basically it's a bifilar wound inductor with a reactance of 50 ohms at
the operating frequency, with shunt capacitors, also of 50 ohms
reactance shunted across adjacent terminals. not too complicated and
cheap to make. not too wideband though.
Saandy 4Z5KS

Quadrature Hybrid Construction
 

"Radra" wrote in message
oups.com...
I am willing to use several hybrids to cover the band, if I must. But
it would be helpful to use broadband hybrids so I don't need to use so
many. I appreciate the reference to the QST article on hybrid
construction. I will build one to see how much bandwidth I can get.
Would like to find a construction technique which yields wider
bandwidth tho. The PSCQ-2-32 from Mini-Circuits has a 3.2 to 32 MHz
bandwidth! Wonder how they do it.

The LO technique is not applicable for my design but it is interesting.
I will have to give it some thought to understand how it works.

Vinton

Well, for that requirement, you need :

G.W. Horn, I4MK, "How to design Wide-Band RF Quadrature Network"
QEX, November 1982, pp5-9.
3-30 MHz quadrature networks designed by VE5FP/VK2BOX

Rick Campbell, KK7B has "SPRAT Technical cartoons #1 and #2" that have
details on single band hybrids, and the component values for them.

W4ZCB

Quadrature Hybrid Construction
 

Radra, unable to contact you off group.

GM. I realize my reference is getting pretty old and may be difficult to
obtain. If you'd like a .PDF of I4MK's 3-30 MHz quadrature 1982 article, I
could send it to you, although it's a fairly large file. Conversely, he's
still up and about and seems to be good in the QRZ call book.

His article yields the equations for a hybrid for any frequency and should
(I think) give you a single solution for your needs.

Regards
W4ZCB

Quadrature Hybrid Construction
 

Harold E. Johnson wrote:
GM. I realize my reference is getting pretty old and may be difficult to
obtain. If you'd like a .PDF of I4MK's 3-30 MHz quadrature 1982 article, I
could send it to you, although it's a fairly large file.

Me too! Maybe you could put it on the web, in case there's more lurker
interest?

--
All relevant people are pertinent.
All rude people are impertinent.
Therefore, no rude people are relevant.
-- Solomon W. Golomb

Quadrature Hybrid Construction
 

I am attempting to contact the author of that paper, G. W. Horn (I4MK),
to see if he will permit me to publish his paper on the web for a few
months. If I am successful, I will post the web link on this list.

I have another paper which may be of interest: "A Broadband Quadrature
Coupler", Microwave Journal, May 1983, pp. 216-219. The authors employ
a pair of four-port directional couplers and a balun. Now all I have
to do is figure out how to construct a four-port directional coupler
for the 0.5-2.0 MHz band!

Vinton