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I've been selecting RF switches, and I've seen some cheap ones from Infineon that are really interesting, but they use MIPI RFFE interface (like the BGMBGS16MA12 from Infineon).
The idea is controlling it with an ESP32 for a small project; however, I didn't find any driver IC nor a software library to control them. What am I missing? Do I need a driver, a dedicated controller IC, or do I need to bit bang the communication?

Tinkering with building an asset tracker to keep track of things in my garage and make sure they generally go back to their right places. I was hoping to put RFID tags on the non metal parts of tools and nic nacs(mostly holiday decorations) in plastic bins and use an rfid reader attached to the side of each bin to check if they’re in there.

I started out with a nucleo board with an nfc expansion board, ordered some tags, and got the code up and running. The board comes with a small pcb antenna and I get about an inch and 3/4 range but I heard that rfid ranges can vary based on a bunch of factors.

I was thinking about replacing the antenna attached to my board as a good place to start.

Am I headed in the right direction?

P.S. This is a hobby project so I’m not looking for an actual asset tracking system.

Hi RF redditors!

I'm putting together some hardware for an RF amp stage ( using this mini circuit part https://www.minicircuits.com/WebStore/dashboard.html?model=LEE-59%2B ) and since I need to amplify from 10MHz all the way to 2G I was already planning for arranging several caps from nF to pF range for AC coupling, when I stumbled upon this ultra broadband cap from Kyocera (https://www.kyocera-avx.com/products/broadband-components/broadband-capacitors/broadband-capacitors-530l-series/ ).

How does a 100nF cap work all the way to 18GHz? Do you have any experience with these DC blockers?

On the same topic, are you aware of inductors to use to feed DC to the drain of the amplifier with the same ultra broadband response?

Thanks and apologies in advance if this is a noob question

I spent the majority of the winter months rack mounting my HP equipment. One rack is populated with a 141T spectrum analyzer and complete gamut of plugins, tracking generators, and preselector. The second rack holds my 8505A VNA system with both 50Ω and 75Ω versions of the 8503 S-parameter test set.

My “DC-to-Daylight” hobby spans both impedance standards, and pretty much all of the equipment in both racks will experience roughly equal amounts of use. As a result, two bottlenecks have emerged; one in each system:

•On the rear of the 141T system, the ‘Aux-A’ coaxial D-Sub port is used for both the 8443 and 8444 tracking generators…wherein, only one generator may be connected at a time, and the cables must be manually swapped should the other generator be used… an ergonomic nightmare in a rack-mount setting.

•A similar conundrum exists on the 8505A system when switching between use of the 8503 A&B test sets. Fortunately, the two rear connections for each test set (HP-IB and a DB-25 test set interconnect) can be managed from the front; simply set both test sets to the same HP-IB address, pipe both DB-25 interconnects through an A/B switcher, and only have one powered up at a time. There is, however, an additional set of frontside connections that are a bit more critical: The four coaxial RF interconnects (RF, Reference, A, and B). While easily accessible from the front, repeated connection/disconnection of these ports will inevitably lead to excessive wear of rather expensive hardware.

For both instances, I’m thinking of building a coaxial switching system that can toggle the connections between modules (much like the DB-25 A/B switcher for The test sets). I’ve yet to come across an ‘off the shelf’ coaxial D-sub 6PDT switch (or even a 4PDT coaxial switch, for that matter), so this will likely be a custom job. Has anyone ever built something like this before?

I'm designing a 10 layer pcb for a SOC There is a 50ohm impedance track between the wifi module and a low pass filter for an antenna. It goes like wifi module -> LPF -> Antenna . When i calculate the trace width creating an impedance profile using altium designer it gives me a width of about 3mil . It seems too small. I cannot change the layer stack. Is there anything i can do ? Maybe serpentine routing helps?

I'm trying to turn ON and OFF two RFID antennas.
The input signal is a sine wave of amplitude 4.8V and frequency 13.5MHz.
The antenna is represented by an induttance of 950nF.
On each line, I'm using four MOSFETs: two for the signal and two for the ground.
Each copy of MOSFET:

• has a common gate. Gates are driven by GPIOs.
• source and drain are linked together.
• between source and drain there is a diode to keep che negative component of the signal (only MOSFETs for the signal).

I need to disconnect two antenna terminals separately.

My electronic circuit is:

MOSFET: turn ON/OFF RFID antennas

The signals are:

• red: input signal
• green: antenna ON
• blue: antenna OFF

Signals

I have a problem.
The signal of the antenna OFF (blue) is not null. Why? How can I change the circuit to cancel the signal?

The starting point is the configuration proposed by NPX AN11314 (Multiple Antennas on Single Reader IC). The project has two TX components: TX1 and TX2.

NPX AN11314 (Multiple Antennas on Single Reader IC)

My project has only one component TX. An antenna terminal is connected to the ground.
If there aren't solutions with MOSFETs, is there another low cost solution to turn the antennas ON and OFF?
Thanks

Hi all,

I have quite a simple RF circuit question regarding the effective resistance of a switch that I want to characterise. The switch is a semi-conductor switch that opens and closes a RF port depending on the voltage applied to it.

I want to see what the effective resistance is of the circuit when the switch is open. I have checked this with a Vector Network analyser on a range from 10 MHz to 100 MHz by measuring the S21 parameter. Data is currently in real/imaginary form.

However, I now don't know how to interpret my data and to work out the resistance that is through this open port What formula should I use? Essentially, I want the exact extremely high 'resistance' that my circuit is acting as.

I basically want to see how good the switch is when it is open.

Im looking to possibly hire someone for a research and development project. I need someone with experience in the Radio Communications field to help me understand and identify some unknown signals.

If there is any crack or free to download available... please let me know

I'm thinking of buying a bench spectrum analyzer to continue my journey learning about RF. I'm an aging hobbyist with no financial constraints. I already have a TinySA and a Nano VNA-H.

The obvious choice would seem to be the Rigol DSA815-TG. Reviews go back 11 years or so, so I'm wondering if there is anything newer and better

This one is a little long, I know, but please bear with me! I had to give this prelude.

I am designing an MMIC power amplifier at 10 GHz. I have two driver stages and a power stage (which is two amplifier stages in parallel connected using a Wilkinson power divider). I am using a GaN process and am designing using ADS. In every stage of my design, I run the simulation at the schematic level using all components provided in the PDK, and I parallelly check the corresponding EM simulation result. I've noticed that the results match 100%, which leads me to believe that even at the schematic level, the software is considering layout layers, spacing etc. Once my power stage was completed, I ran the EM simulation with all the GSG and DC pads included, and I got the result I was expecting, after which I proceeded to design the driver stages.

I am at the end of my design now, where I've designed all stages, connected them together and obtained the result in the schematic. But when I run the EM simulation of this,

1. I've completely lost the matching. It hasn't shifted- it just isn't there.
2. typically, the gain curve as we know it is constant for a while, after which it undergoes gain compression. But I'm getting something very weird (image attached) and an extremely negative value.
3. it seems to me that the circuit is not considering the DC voltages that are being applied at the transistor drains and gates- but I could be wrong about this.

This is my MTech thesis and I have about 3 weeks to submit my results. I'm stuck here and don't know how to proceed. Please help!

I've also attached an image of the layout for reference.

PS: Someone suggested that I run a transient assisted HB simulation to observe at what time the system reaches steady state and what the results are at that point. I know how to run a TAHB in ADS, but is there a way to view the results with respect to time?

Has anyone tried to connect to antenna together? I am trying to collect signal on one and send it out the other. Without the use of amp, or switching gear. I could see a few complications possibly. But in theory?

I'm trying to design a power amplifier that can help amplify the RF signals from Intel Dual Band Wireless-AC 8265NGW. Similar to how these amplifiers from sunhans and others do. I tried getting eval kits from Skyworks, SKY65900-11-EVB, SE2576L-EK1, SE2623L-EK1, SKY66292. But to my dissapointment none of them are able to amplify the signal effectively. (I don't think they are amplifying at all).

Initially, I was directly giving the output of the Intel 8265 to the Skyworks eval boards. But later found out that the boards cannot handle more than 0dB of input. So, I started putting attenuators and testing. I tried with different off-the shelf attenuators, and would see the gain go up by 30dB or so. But, I wouldn't see the Wifi signal range getting improved at all (As if there was no amplification. I still don't know how the sunhans amplifiers do these (because they are directly able to take the output of the Intel 8265 boards and amplify, without the need of any attenuation).

I'm not sure what I'm doing wrong. If anyone has any idea on this?

Thank you for all the help.

Is there a common way of doing that with a network analyzer?

​

I am working with a customer on a project that requires AWR. Cadence OnCloud is a good alternative to purchasing a seat. I purchased 99 tokens last week, which, per their website, should be 90 hours of access (even the FAQ says 1.1x burn rate). After using it one day for 5.5 hours, I expected to see around 6 tokens consumed (5.5 * 1.1) - instead I consumed 13 tokens.

After trying to use their support - hint: you can't unless you pay extra - I was finally able to send a ticket to understand the extra consumption.

Their response: we changed our burn rate 2.475x back in February.

So instead of 90 hours, I actually have 40 hours...

I am still waiting to hear back from support regarding their advertised rate. In the meantime, others should treat this as a caution if you're considering OnCloud. $990 for 40 hours is ridiculously expensive!

Hi everyone, I want to design a transparent planar antenna for my project and use ITO as the transparent conductor.

I searched up this material in the material library and unfortunately it doesn’t exist there so I need to define it myself and I don’t really know what parameters to define save from the conductivity…I tried to look for some electrical data-sheets for this material and I couldn’t find any.

I would like some help from someone that had to do it before / knows a good source from which I can find this info.

Thanks!

I want a generalized opinion and ideas on how Experimental and Numerical Analysis methods can be used to determine the currents, voltages and losses in an Inductive Power Transfer System. I am currently in the stage of ideas brain storming on this topic, so your help would really make a difference. Also please suggest some sources relevant for this topic

Hello, I've been asked to design and simulate an antenna from a selected paper. I've been also asked to match the solution that are provided in the paper however I don't know how to get the phase response to frequency plot that I've provided in Ansys HFSS. I've tried it with MATLAB using RFtoolbox kit however I couldn't find a way for it either. I am awaiting on your suggestion, thanks for reading and helping out.

https://preview.redd.it/wl0sxo6b99xc1.png?width=622&format=png&auto=webp&s=edd1d6beb70abf0c9bff1fbe055ffee787ca2103

The version 1.0.0 of scikit-rf has been released! 🎉

This major release is the result of 14 years of developement by around 80 contributors. In the recent months, the codebase and its API has been reorganized, cleaned and optimized, to provide a robust and well-tested RF/Microwave engineering package.

The version 1.0.0 does not include major changes with respect to the previous versions. This number 1.0.0 just aims to show for current and future users, that the scikit-rf package has now reached a significant level of maturity, a sufficient stable and performant state, ready for production use. It means that the developers consider scikit-rf to be ready for a widespread adoption.

Of course, scikit-rf development will continue, with new features, bug fixes, improved performances, in its subsequent versions.

Looking ahead to future release, we have releases a survey is intended for all the users of scikit-rf, in order for the developers to get some feedback, to determine what are the functionalities used the most and the less, the ones which could be improved, and to determine the directions for the future of the package. Thank you for your time in answering this survey. This should take 5 minutes and your feedback will be super useful!

https://forms.gle/t3FzCRkuy6PsFRwi9

I read that generally the far field begins about 3-5 wavelengths from the antenna, but in some exercises in textbooks I've read have shown that the near field can extend several meters from an aperture antenna that has cm wavelengths.

I want to create a circuit that does the FM modulation and demodulation using basic electronic components like resistors capacitors and diodes. I have seen tutorials online but most of them use 555 timers or CD4046 IC. Can somebody please direct me to any tutorial/article that explains the FM modulation and demodulation by making it using basic electronic components

I designed an inductor and generated an s parameters file from an EMX simulation.
How to plot Q and L using "nport" component?

I have a bunch of RFX2401C lying around (around 30 or so). I am wondering, if I could directly cascade them. With a single one I get at best -40dbm. I target around -20dbm as before. I Routed the Antenna output pin into the RX/TX Input pin, paralleled the TX Enable pins for both and upon connecting I was greeted with a horrible -65dmb at best. So I would say I blew both frontends. I however did not work cleanly and shorted the Antenna output of the second stage to ground. Ouch. I am not sure how critical this is at 2.4GHz however. But well... Getting no amplification at all means I blew both Frontend Modules for sure as it is just as weak as if there is no FEM installed at all.

​

So did I just kill the FEMs with a dead short on the output (roughly 20mm out of the IC) or did they die, because they cannot be cascaded and will no matter what destroy themselfes with that? The Max input power of the RX2401C is over 0dbm (not sure why anyone would need such a hich input power, if the amplifier out cannot even get to this level on the output - its like a weak-plifier in such a configuration). Is it just that it would require a filter network? For a single stage network I just put the FEM in the same position as the original FEM, so the output filters and input filters are likely close to what they need to be for a single stage Wifi 2.4G Frontend in this application. Did anyone ever try this and should it work? I do not want to waste 2 FEM and Deadbug Wire solder this all again, if it is supposed to blow up again anyways.

Hey folks.

I am part of a group at my college that has designed a RF board as a part of a larger project. We want to quantify the performance of the board to understand if we are doing anything right or if we have to completely change what we are doing. Nobody of the team has ever really measured something like this, so we are both lacking equipment and experience. Great combination :)

The goal is to measure the power that is put out by the board on each channel and then compare it to the calculated ideal value to get the losses we have by missmatch, insertions etc.

With that goal in mind, I currently face the challenge of actually measuring the output power accurately enough. Sadly the group has no power analyzer and the contact person at the only institute I could ask is currently gone on a conference.

We have the following equipment:

- SAA2 NanoVNA v2
- Adalm Pluto
- A AD8317 breakout board from amazon
- Up to 90dB of attenuators (3x 20dB + 1x 30dB)
- SMA cables, multimeter, logic analizer, power supply etc.

My main challenge is to find some signal with a known dBm to compare and calibrate the AD8317 against. From what I´ve gathered / read, none of the other devices can actually output at a certain level, but I would love to be corrected about that.

So, Im asking here: Is there some trick, or idea any of you have used to successfully produce a signal at a given frequency, with a given power level without a 10k€ spectrum analyzer / signal generator? Or something I could fundamentally do differently?

The relevant specs are:

- Center frequency: 2.4 GHz

- Width of the band we want to measure in: 500 MHz

- Theoretical output power: 27 dBm

​

Thanks for reading.

Hello I need help with this problem please :

Problem:

A transmission line with a characteristic impedance of Z0=75 Ω is connected to a load with a normalized admittance of yL = gL - j0.5. A short-circuit stub of length l = 0.375λ is connected at a point a distance d from the load.

Task:

1. Find the impedance of the transmission line at the connection point a-b before the stub is connected.

2. Find the impedance of the transmission line at the connection point a-b after the stub is connected.

3. Find the distance d from the load to the connection point a-b.

4. Find the resistance RL (the real, non-normalized part) of the load impedance.

5. Find the reflection coefficient (in two ways: using a Smith chart and also by analytical calculation).

this is the problem fig :

שלום

that is the solution :

Smith

the calculations of my professor

I have been trying to understand it for 3 days but I have no idea how he found some of the parameters:

1.what is the value of gL and how to find it ?

2. why is Yinsc=J

3.what formulas do I miss here and what is the stuff the missing between the lines of the solution ?

I am usuing smith chart a lot for time but this RF exercises are killing my brain so please help me

post Scriptum

I didn't find the forum rules anywhere, so I don't know if I'm breaking some of them, so if it's possible, please don't delete or close the post for me, and if I'm not in the right forum, I'd appreciate it if you could move my post to a forum that can help a desperate student who is studying days and nights for his final exam in designing RF components.

thanks a lot and happy passover/pasha's holidays

They are out of stock everywhere, on some websites they're $186, on others they're $500+