Questions tagged [microwave]
Microwaves are radio waves with a frequency from 300MHz to 300GHz which corresponds to a wavelength of one meter down to one millimeter. Often in RF engineering however it is used to refer to a narrower region such as 1 to 100GHz.
558 questions
0
votes
0
answers
33
views
Advice on S Band RF GaN transistor with MWO libraries
I'm designing a microwave class F power amplifier, and I'd need a transistor in the 2.7-2.9 GHz range with at least 10 dB gain (16 dB would be ideal, but feel free to advice anything above that ...
- 21
1
vote
1
answer
110
views
Would this motor growler from a microwave oven transformer work? (Drawing included)
I want to make a growler to test motor rotors / armatures.
I want to use a microwave oven transformer, removing the secondary coil, cutting the centre out (where the two red lines are) and removing ...
- 21
0
votes
0
answers
49
views
Do you need to enable Vdc for s2p simulation in ADS?
I am designing an evaluation board using MAAL-011078
Low Noise Amplifier from their 4.4-4.9GHz reference design on Page 15.
Do I need to enable 3 volts Vdc for simulation?
- 1,127
3
votes
2
answers
1k
views
Does cell phone only receive (one way communication) or receive and transmit microwaves (two way communication) during download?
Does cell phone only receive (one way communication) or receive and transmit microwaves (two way communication) during download (for example when you watch YouTube)?
Is short, what are differences in ...
- 133
3
votes
6
answers
2k
views
Have major manufacturers been known to wire up circuits wrong?
I took apart a Panasonic microwave for the sake of using components for projects. I know what I am doing because I have industrial engineering experience.
I did not notice it at first (hence I ran ...
- 213
1
vote
1
answer
128
views
RF Analysis of a three port network
I was wondering if anyone could help me understand how to analyze an RF transmission line circuit that I saw in a design used to detect power. It is a three port network that has two transmission ...
- 353
1
vote
1
answer
131
views
How to evaluate input impedance on HFSS
I have simulated a 3D structure in HFSS and the figure below shows the "schematic" of the structure: there is a two-ports network and two transmission lines connected with different ...
- 11
1
vote
1
answer
113
views
What's the (seemingly) sinusoidal indentation on a microwave's oven waveguide?
This waveguide has a (my guess) sinusoidal indentation on the face opposite the magnetron's output. It seems to be roughly half a wavelenth in diameter as measured on the surface of the waveguide.
- 51
1
vote
1
answer
155
views
What type of RF oscillators are used in solid state microwave ovens?
In particular, do they use Gunn oscillators with LDMOS RF amplifiers, or do they use lower frequency oscillators with frequency multipliers?
- 744
1
vote
0
answers
72
views
Chebyshev bandwith filter realisation on microstrip coupled lines
i'm currently writing a diploma, in part of which i have to synthesize Chebyshev filter on microstrip coupled lines, on 6th degree and 9GGhz f0. I did it on on C and L elements using default formulas, ...
- 21
5
votes
1
answer
170
views
Controlled impedance microstrip poor return loss
I have designed a microstrip PCB to confirm that my calculations are correct and roughly measure the signal loss of a 45 mm microstrip. However, the return loss (S11) seems to be very high (~-11 dB) ...
- 69
0
votes
3
answers
199
views
Why does Reflection Coefficient depend characteristic impedance that isn't there?
In this system, (Z_0) is the impedance used to measure the amplifier’s S-parameters. When measured, both the source and load impedances were set to (Z_0), typically using a vector network analyzer.
...
- 9
4
votes
2
answers
222
views
Identification: SMD Transistor marked "△T 03" , used on Galanz Microwave's Digital Programmer Circuit
I need a help in identifying this SMD transistor. It have a marking of what seems to be a logo of the letter T inside a triangle, followed with “03”. This particular transistor measures around 1.3 x 2....
- 93
1
vote
1
answer
83
views
Wave reflection in connected Transmission lines
Figure 1: Three connected transmission lines
In the circuit above, three transmission lines are connected together.
Would a forward wave be ...
- 1,335
-1
votes
1
answer
92
views
S-matrix of a 3-port circular network
I have 3 sub-networks, which are described by ABCD matrices.
I connected them together to form a 3-port circular network, described as follows:
Port1 → ABCD1 → Port2
Port2 → ABCD2 → Port3
Port3 → ...
- 13
1
vote
1
answer
66
views
Two-photon Raman transition via phase-locked microwave signal generator
I am trying to implement a two-photon stimulated Raman transitions between two Zeeman sublevels of Cesium(Cs), namely the (3,3) and (3,1) states. These two states will then be coupled via intermediate ...
- 69
0
votes
0
answers
75
views
Reflections on a PCB
We have designed a PCB which consists 6 RF chains. In one single chain it consists of limiter + LNA + SPDT.
We are getting good S parameters (gain, return loss.) The only issue is that we have ...
0
votes
2
answers
132
views
Single stub matching: single stub which has different characterstic impedance than the line?
How do we use smith chart to match a transmission line using a single stub which has different characteristic impedance than the line?
Can we denormalize the load admittance seen a distance d and ...
7
votes
3
answers
1k
views
Can a microwave antenna detect single microwave photons?
In a lecture about satellite sounding our professor explained how microwave radiance is measured typically on satellites: There is an antenna behind a parabolic mirror and the received signal is ...
- 834
1
vote
0
answers
151
views
Find IC used in Microwave motion sensor (701E)
I am working on a project that involves 5.25Ghz microwave motion sensor, to properly get the results i need to integrate the microwave sensor with arduino.
I found a device having the same specs but ...
- 11
0
votes
3
answers
192
views
Why does the RF Bypass capacitor have to have larger capacitance than DC Block ones?
I'm analyzing the following circuit.
The S-parameters are listed below.
However, when I change the capacitance of C1 back to value all the other capacitors have (12 pF), the S-parameters look like ...
- 59
0
votes
1
answer
145
views
Not sure how to analyze a biased bjt transistor in AC
I'm trying to analyze the circuit below.
According to the superposition theorem, I can short circuit one voltage source at a time and then add the voltages both supply in order to find the final ...
- 59
0
votes
3
answers
257
views
Are microwave oven transformers usually bigger if designed for 230V vs 120V?
Consider a 1kW microwave oven designed with versions for both Europe and USA. The 50 Hz of Europe should theoretically force a slightly bigger, and more expensive, transformer, but what about the ...
- 916
0
votes
2
answers
82
views
The Theoretical and simulated S parameters of a TXline
If we consider a simple TXline of length \$l\$ and characteristic impedance \$Z_1\$, theoretically, its S parameters are
$$
S_{11}=\frac{Z_1-Z_0}{Z_1+Z_0}
$$
$$
S_{21}=e^{-j\theta}
$$
$$
S_{11}=S_{22},...
- 11
1
vote
1
answer
144
views
How would I use a Smith Chart and L-network to set input admittance of a circuit network?
I'm doing the practice problem pictured below:
Find d1 and d2 with:
$$Z_o = 50 \Omega \hspace{5mm} Z_L = 100 \Omega \hspace{5mm} f=10GHz$$
So that:
$$Y_{in}=20\angle30^o\hspace{1mm}mS$$
I summed up ...
- 416
2
votes
1
answer
188
views
Rough feasability of 1W of microwave power in a 1mm^3 region at 10GHz?
I understand, from a previous question, that the generation and simulation of near-field microwave electronics is challenging.
Before doing a full simulation, is it possible to get a ballpark estimate ...
- 370
1
vote
1
answer
131
views
Is there a simple approximation for B-field strength of a loop antenna when driven at 10 GHz?
I have a near-field loop antenna that I'm applying a microwave field to at 10 GHz. I'd like to have it interact with a small magnet that is much smaller than the loop. Here's a picture with the little ...
- 370
3
votes
2
answers
99
views
Numbers in Generating Phase Coherent Electronic Systems
I am reading the following paper 'Störmer’s numbers in generating phase coherent electronic systems' written in 1969.
More or less I understand that
in microwave applications there is clearly a use ...
0
votes
1
answer
71
views
How to solder the central pin of the TGA 2214-CP microwave amplifier
Here is datasheet of the TGA 2214-CP amplifier: TGA 2214-CP
The pins can be seen on page 11. It turns out that pin 7 and 9 are very close to the central pin 1, as well as pin 8 and 10 to pin 2 (about ...
- 1,968
0
votes
0
answers
41
views
Finding old rf components datasheets
I've just received a load of old rf components used for X-W band and am at a loss for where to find information on them. A lot of the parts are from TRG division of Alpha Industries Inc. and it seems ...
- 11
6
votes
2
answers
735
views
Simple method to generate nonuniform magnetic radiation in a region of 0.5 mm?
I need an antenna that can generate a nonuniform magnetic field over a very tiny region at 5 GHz. (By nonuniform, I mean that the field vectors are diverging as much as possible. I will place this ...
- 370
0
votes
2
answers
3k
views
Microwave magnetron connections reversable F, FA?
The two connections on a microwave magnetron are labeled F (filament) and FA (filament anode), both being either ends of a heated filament powered by a 3V AC supply, and the FA connection being ...
- 857
0
votes
1
answer
58
views
Troubles in understanding the TGA2214-CP microwave power amplifier datasheet
The datasheet of the Qorvo microwave amplifier is here.
I have troubles with the following points:
In p. 9, they give a schematic of the way to mount the amplifier (I believe).
But at the end of the ...
- 1,968
0
votes
1
answer
273
views
Time average stored electric energy in a volume
I am studying the book Microwave Engineering Third Edition by David M. Pozar. At the moment I am at chapter 1.6. At the beginning of this chapter Pozar states that
In the sinusoidal steady-state case,...
- 53
1
vote
1
answer
201
views
Substituting for 1N34A diode to change range of microwave detector
In connection to an earlier question, this DIY device for detecting "mini radio" EMF seemed like it might work to detect microwaves generally, assuming diodes exist to replace the 1N34A ...
- 189
1
vote
1
answer
240
views
How can I visualize 24 GHz RF on a screen?
Is there a (preferably inexpensive) way to visualize/image 24 GHz RF from a radar gun (of the type used to check baseball speeds) on a screen?
Here are some examples of what I mean, for other ...
- 189
0
votes
1
answer
143
views
Add resonances to monopole antenna
How can I design a "simple" low frequency monopole antenna with multiple resonating frequencies?
I elaborate...
I need to design a sort of monopole antenna with multiple resonating ...
- 103
0
votes
2
answers
188
views
S-parameter of cascaded system, port impdance
I have a question about the s parameter of the cascades system.
Assuming that there are two system A,B as shown in the figure and each has an s-parameter measured at 50ohm port,
I understand that the ...
- 1
1
vote
0
answers
58
views
De-Embedding Structures
I am trying to de-embed the attached ports and gnd plane to measure characteristic impedance of transmission lines in between the two port/small TLs.
I have tried techniques on
https://www.doe....
- 11
0
votes
2
answers
510
views
EMF Meter: difference between AC magnetic, AC electric, and RF Measurements
let's consider this EMF Meter. Regarding its description, I have some doubts regarding what it is physically trying to measure:
Detects all three types of EMF pollution: AC magnetic, AC electric, and ...
- 3,660
4
votes
2
answers
342
views
Microwaves going through a hole - attenuation?
We have a microbalance that has a "hangdown wire" supporting a sample pan in a steel chamber. We need to heat this with microwaves, most probably at the common 2.4GHz of microwave ovens.
...
- 14.4k
1
vote
1
answer
193
views
Two-way Wilkinson divider: why is R₂ = Z·K and R₃ = Z/K?
I am trying to understand why R2 = K · Z0 and R3 = Z0 / K.
I get the power is not equally distributed over both ports, but why is one multiplying and the other dividing?
- 193
1
vote
1
answer
947
views
Intuitive explanation of shorted stub behaviour
Can someone please give me an intuitive explanation of shorted stub behaviour?
NOTE: This is not a duplicate of Intuitive explanation of open stub behaviour which has been narrowed to focus on open ...
0
votes
2
answers
871
views
Intuitive explanation of open stub behaviour
Can someone please give me an intuitive explanation of open stubs?
I have the length-based mathematical derivation and explanation from my textbook, but I am looking for an intuitive one.
For example,...
4
votes
2
answers
456
views
Can I test the EM shielding of a material with a spectrum analyzer?
I am a hobbyist and I am intersted in testing some materials for their ability of reflectance/absorbance/transmittance for microwave radiation and I want to know if a spectrum analyzer is suitable ...
- 95
1
vote
0
answers
83
views
Integrated Circuit z-impedance
I have an OBU (On-board Unit) circuit and it has a DSRC (Dedicated Short-Range Comm) IC, but I don't have any information about the IC from S11 and Z etc.
I want to ask how can I find the Z-impedance ...
- 21
0
votes
1
answer
111
views
Finding datasheets for relatively new looking components but nothing appears from search
Some context: I acquired some RF components from the family of an old RF tech that passed. I am currently adding the parts and datasheets to my inventory but for the following parts I was unable to ...
- 402
0
votes
3
answers
116
views
AD application note MT-097
Below is the statement from AD application note MT-097.
I have see this explanation many places.
But no one explains how transmission line effects comes when rise time is smaller than 2*times ...
- 4,055
1
vote
0
answers
62
views
Matching network for two-port with internally matched inputs/outputs
Background
I had a lab in school where we were given an LNA with inputs/outputs matched to 50Ω, that will be connected to a 50Ω system:
The task was to design the input and output matching networks:
...
- 111
6
votes
2
answers
990
views
Monopole antenna with coil design
(Note: I'm a beginner in antenna theory)
When browsing for low cost antennas online, there seems to be class of monopole antennas that have a coil or two built into the monopole, and are advertised to ...
- 223