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Impedance Matching Dipole

23 Threads found on edaboard.com: Impedance Matching Dipole

Matching Network with dipole antenna

Hi all, Please, How can I use Lumped element on a port for impedance matching purpose between a discrete port and dipole antenna in CST? How can I connected the Lumped element, discrete port and antenna together ? what I use to connected them?

Without looking at your design, I'd have to say that it's expected. Commercial Yagi antennas typically have some kind of matching network (Gamma, Delta, etc.) to tune the antenna impedance to near 50/75 ohms.

Balun for 437MHZ narrowband dipole

................... P.S my dipole is precisely 50 OHM and so is the coaxial cable so no need for impedance transformation. I only need to eliminate the coax shield currents. How did you achieve that ? ... dipoles are 75 Ohms by nature ( folded ones 300 Ohms) ... what impedance matching did you do ? Dave

How to calculate the matching network for a dipole antenna short than the half wave

You can get a formula for the complex impedance of the antenna from Wikipedia under "Short dipole" on the "dipole Antenna" entry. and there is a section on "General impedance can use a calculator on it. You will be looking to

Dipole antenna, balun and impedance matching

Hello, I'm trying to make a dipole antenna for UHF (433 MHz). I have a 50 Ohm unbalanced output so I need to balance it and do an impedance matching to get the best performance possible. I bought some Minicircuits' ADT1.5-1 ( ) to do the job. I made a PCB, soldered the transformer and the legs of th

Printed dipole mounted on reflector ground plan : XFDTD 7.0

You're sure the ground plane is λ/4 away from the dipole? There's a great tutorial in Balanis on dipole arrays and impedance matching.

Folded antenna + balun : matching question

Dear all, I have a question about matching a printed folded dipole. I am working at 2.45GHz My antenna is connected to a 50 ohms /50 ohms balun, then connected to a 2-ports VNA, for s11 evaluation. At the frequency of interest, the impedance is Z; is this the impedance of the antenna seen from the VNA? Because I need (...)

how to impedance match each array element in HFSS?

I am trying to impedance match a 5-element dipole array in HFSS using the Active Z re and im values, but I am not getting good S11 with it. How do you achieve good impedance matching of array elements? Please help all you HFSS experts out there.

Impedance matching log-periodic

Because the log periodic use a bunch of parallel dipoles, its impedance is actually lower than of a λ/2 dipole (which is about 73 ohms)

Why do we use a folded dipole in Yagi Uda antenna?

I was reading about this Yagi Uda Antenna and I came across this-- "If the distance between driven and parasitic element is decreased the it will load the driven element, irrespective of its length. Thus input impedance at the input terminals of driven element reduces. This is why a folded dipole is invariably used as driven element so that r

Practical matching of complex input impedance of a dipole

A standard method (but narrowband) is to add a length o 50 ohm transmission line to rotate your complex impedance so that the imaginary part goes to zero. At that point, read the real impedance and use your quarterwave transformer to match that.

S2,1 and S1,2 parameters in CST

Hello All, In an attachment to this message, dipole antenna model is attached. can any body have suggestions, how to improve s21, s12 parameters without changing distance between dipole antenna.impedance matching is almost perfect.

1. Yes, the impedance changes with frequency. And some formulas for antenna impedance you can find only at their resonant frequencies. For example a dipole antenna: 73 + 43j at its resonant frequency. At other frequencies, the derivation is complicated and requires lots of tedious steps, therefore usually we measure the (...)

impedance matching for dipole antenna @ UHF

Probably is about a small printed dipole, and you can use a gamma match, which allow tuning the impedance match of the antenna.

how to assign resistance to a feed line in HFSS?

I would like to assign 1000 ohms to a feed line in HFSS? How do I do that? Also, how long and wide should the rectangle be? I am building a quarter wave transformer for a dipole antenna to impedance match it. I am using a lumped port to excite it, but my advisor wants me to build a matching network with a quarter wave transformer with (...)

Impedance Matching for 915MHz

Check the impedance nature of monopole antenna around 915MHz. If you find that it is not matched to 50 ohm then based on the bandwidth you may match with simple L and or C or L section or PI section etc. Smith chart can help you.

RF modules - external components, correct value of antenna

This is kind of module manufactured on a boat. There is no specification on the datasheet for RX-TX antenna impedance. Give a try without matching components and luckily it will work for the distance you are looking for.

Need advise with impedance matching with RF amps and antenae

So, I am building a high powered FM transmitter for out in the ocean. I found a complete FM transmitter on a

Positive and negative reactance in dipole antenna

It seems you have a mismatch at 199.25 MHz. 44.5-j32.03 ohms gives a return loss of 9.7 dB = VSWR 2.0. Is your Yagi antenna design really resonant and optimized for 199.25 MHz? How does the input impedance vary over the frequency range from 150 to 250 MHz? How about the gain over this freq range? You have to improve the matching of the radiat

HFSS: Complex Impedance to Differential Coplanar Striplines

Hi, I am new to HFSS. I am doing matching filter network to balance dipole antenna. I know ADS but new HFSS. Top=Air Copper: 17um Substrate:RT-Duroid 5880 Ground: No Bottom=Air Is anyone know how to assign an excitation differential port with Complex impedance to Coplanar Stripline which is <1mm next to each other? Complex (...)

folded monopole antenna

Hi: I think one more reason people use folded dipole is for matching. A typical dipole antenna with normal radius has a Z = R + j X = 75 ohms at the resoance defined as jX = 0. A folded dipole's impedance will be about 4 times as big. It is close to 300 ohms and that is why many old TV sets used folded (...)

pls help, i am a newbie in dipole antenna design

The impedance of a dipole in free-space is approximately 72 ohms. The impedance of a microstrip dipole is affected by the substrate. To match the dipole you need a balun.

Question about elements impedance in dipole antenna design

The SWR bandwidth of a folded dipole is less than a cylindrical dipole of the same spacing between wires. It is very difficult to make a dipole of 10% bandwidth of SWR under 3:1. On the HF band frequency assignments for a station are in narrow ranges. They use dipoles in parallel, one resonant for each band. The (...)