267 Threads found on edaboard.com: Input Impedance Antenna
I would guess the transmission line Z is around 70ohm like other 1/4 wavelength dipole antennas.
According to literature, it's more complicated. As a simplified idea, imagine that the characteristic feed line impedance loaded by the dipole elements equals the antenna input impedance. So it's always higher (...)
RF, Microwave, Antennas and Optics :: 03-07-2017 07:47 :: FvM :: Replies: 2 :: Views: 449
how to calculate the minimum separation between body and wearable antennas. if it's very small the absorption because of body will be high and and also it effects the input impedance and the radiation pattern of the antenna.
one good approximation is to be keep the distance of (2d2/lambda) from the body for which results (...)
RF, Microwave, Antennas and Optics :: 01-04-2017 10:34 :: prateek3790 :: Replies: 2 :: Views: 502
I need simulate an antenna in HFSS for RFID. The internal impedance of IC at 915MHz is 12.8-j248 (NXP UCODE7). This is a serie impedance.
To simulate this impedance I use a Lumped port with equivalent parallel resistance Rp ~ 4.837K and a capacitance of 0.7pF in parallel using a lumped RLC. Both in parallel connected to a (...)
RF, Microwave, Antennas and Optics :: 12-21-2016 11:15 :: leomecma :: Replies: 1 :: Views: 919
The antenna efficiency (or radiation efficiency) can be written as the ratio of the radiated power to the input power of the antenna
The total efficiency of an antenna is the radiation efficiency multiplied by the impedance mismatch loss of the antenna: (...)
RF, Microwave, Antennas and Optics :: 12-06-2016 09:11 :: Orange_1888 :: Replies: 0 :: Views: 419
I would like you to clarify a point that I don't understand very well.
when an antenna resonate it means that the Imag part of the impedance is equal to zero, but while reading I found a paper with totally different results which I am attaching the confusing figures of the complex input impedance of the (...)
RF, Microwave, Antennas and Optics :: 11-14-2016 16:37 :: B4M :: Replies: 7 :: Views: 748
there are differential op amps that actually work pretty high in frequency, like 2.3 GHz for the ADA4927-1 from analog devices. Maybe use those. You could convert to single ended signal after the input op amp.
RF, Microwave, Antennas and Optics :: 09-22-2016 02:23 :: biff44 :: Replies: 7 :: Views: 692
Problem is also that the bridge requires sine rather than square wave input. A filter (e.g. low-pass) is required. Could insert an amplifier too.
RF, Microwave, Antennas and Optics :: 09-19-2016 06:32 :: FvM :: Replies: 8 :: Views: 694
Hi every one!
The input impedance of a single ended antenna is usually assumed to be 50 ohm, I wanna know what is the typical input impedance of a differential antenna? I mean if I want to match the impedance to what my PA needs, what impedance must be (...)
RF, Microwave, Antennas and Optics :: 08-18-2016 10:59 :: sohaee :: Replies: 0 :: Views: 317
Can you explain about the input impedance of the antenna(if possible provide some video links)?
Elementary Electronic Questions :: 08-10-2016 10:12 :: harish1995 :: Replies: 0 :: Views: 0
Inverted-F antenna it will work better than most of chip antennas.
Your inverted-F design should work fine, mainly because you have available a solid ground under the antenna (which is a main requirement for this type of antenna).
The antenna might need some input impedance (...)
RF, Microwave, Antennas and Optics :: 08-05-2016 13:50 :: vfone :: Replies: 5 :: Views: 521
Why does the manufacturer specify both the input and output impedance of the balun?
A balun can have various impedance ratios between balanced and unbalanced ports.
Usually the input impedance of a full-wave loop antenna is about 120 ohms, so for a given 50 ohms unbalanced port you need a (...)
RF, Microwave, Antennas and Optics :: 07-26-2016 08:21 :: vfone :: Replies: 13 :: Views: 1084
I tried to create a loop antenna, consisting of a single closed loop for 144.3 MHz. I wanted to set the diameter so the real part of the input impedance was 50 Ohms, and then tune out the inductive part with a capacitor. So I set up this HFSS model, and found a radius for the loop where the input Z is 50 + j X Ω. So I (...)
Electromagnetic Design and Simulation :: 07-22-2016 12:24 :: drkirkby :: Replies: 6 :: Views: 568
S11 of the antenna and the transmission line impedance, they are different things.
Measure the impedance of the transmission line alone, and later measure the input impedance of the antenna without the feeding transmission line (if is possible).
Measure the real Er of your FR4 PCB, because (...)
RF, Microwave, Antennas and Optics :: 04-26-2016 09:32 :: vfone :: Replies: 4 :: Views: 740
I have an UWB antenna that is composed of double sided substrate. I noticed that when i round the lower vertices of the upper side (patch) or the upper vertices of the lower side (ground) the matching improves, i reviewed the imaginary and real part of the input impedance and i found that they do get improve as the rounding (...)
Electromagnetic Design and Simulation :: 04-16-2016 11:58 :: KawtherHamad :: Replies: 0 :: Views: 423
I designed a simple corner reflector with HFSS and I set terminal impedance to 75 ohm.Here is my Hfss output S11 and input impedance of my antenna.
(So at F=8 Gighz we have S11=Gama=10^(-10.7358/20)=.2905
(as you see at the F=8Ghz image part is approximately around 0 and so w
RF, Microwave, Antennas and Optics :: 02-25-2016 21:07 :: baby_1 :: Replies: 0 :: Views: 729
I do not have access to the fulltext of the following two papers. Anyone can help? Thx in advance!
1) R. F. Schwartz, input impedance of a dipole or monopole, Microwave J., Vol. 15, p. 22, Dec. 1972
2) J. B. Andersen, Admittance of infinite and finite cylindrical metallic antenna, Radio Science, 3, 1968, pp. 607-621
RF, Microwave, Antennas and Optics :: 02-25-2016 01:45 :: streamlet :: Replies: 0 :: Views: 17
what is antenna input impedance variable in HFSS? Terminal Port Z0 or Terminal Z parameters?
Electromagnetic Design and Simulation :: 02-19-2016 07:16 :: baby_1 :: Replies: 17 :: Views: 2597
If the real input impedance of your antenna is actually 0.05 ohm, start with redesigning the antenna. Matching this tiny radiation impedance is a helpless undertaking.
RF, Microwave, Antennas and Optics :: 02-08-2016 07:45 :: FvM :: Replies: 14 :: Views: 2320
you need to plot the input impedance of the antenna which is, in the case of single port network, Z11. The real part should be around 50 and the imaginary part should be crossing zero at that point. An alternative way is to plot S11 and the antenna is considered to be matched when S11<=-10dB.
RF, Microwave, Antennas and Optics :: 01-07-2016 06:19 :: moh.haroun :: Replies: 1 :: Views: 1130
coaxial fed in place of microstrip fed, i never tried it before. usually fed determines the input impedance of the antenna. like if you find my comments are helpful.
Electromagnetic Design and Simulation :: 12-29-2015 17:42 :: pragash :: Replies: 4 :: Views: 1053