Collaborate Disseminate
Do high voltages affect the resonant frequency of a crystal? Honestly, we never thought about it, but [Joe] did and decided to risk his analyzer to find out. He started …read more Continue reading The Crystal (High Voltage) Method
In general, you get what you pay for, and if what you pay for is a dollar-store WiFi antenna that claims to provide 12 dBi of signal gain, you shouldn’t be surprised when a rusty nail performs better than it.
The panel antenna that caught [Andrew McNeil]’s eye in a …read more
Continue reading The Rusty Nail Award for Worst WiFi Antenna
[Steven Merrifield] built his own Scalar Network Analyzer and it’s a beauty! [Steve]’s SNA has a digital pinout matching a Raspberry Pi, but any GPIO could be used to operate the device and retrieve the data from the ADC. The design is based around a few tried and true chips …read more
A while back, I posted a review of the Analog Discovery 2, which is one of those USB “do everything” instruments. You might recall I generally liked it, although I wasn’t crazy about the price and the fact that the BNC connectors were an extra item. However, in that same post, I mentioned I’d look at the device’s capabilities as a network analyzer (NA) sometime in the future. The future, as they say, is now.
In its simplest form, there’s not much to an NA. You sweep a frequency generator across some range of frequencies. You feed …read more
Continue reading Analog Discovery 2 as a Vector Network Analyzer
Instrumentation has progressed by leaps and bounds in the last few years, however, the fundamental analysis techniques that are the foundation of modern-day equipment remain the same. A network analyzer is an instrument that allows us to characterize RF networks such as filters, mixers, antennas and even new materials for microwave electronics such as ceramic capacitors and resonators in the gigahertz range. In this write-up, I discuss network analyzers in brief and how the DIY movement has helped bring down the cost of such devices. I will also share some existing projects that may help you build your own along …read more
Instrumentation has progressed by leaps and bounds in the last few years, however, the fundamental analysis techniques that are the foundation of modern-day equipment remain the same. A network analyzer is an instrument that allows us to characterize RF networks such as filters, mixers, antennas and even new materials for microwave electronics such as ceramic capacitors and resonators in the gigahertz range. In this write-up, I discuss network analyzers in brief and how the DIY movement has helped bring down the cost of such devices. I will also share some existing projects that may help you build your own along …read more
[Shahriar] recently posted a review of a 6.8 GHz network analyzer. You can see the full video — over fifty minutes worth — below the break. The device can act as a network analyzer, a spectrum analyzer, a field strength meter, and a signal generator. It can tune in 1 Hz steps down to 9 kHz. Before you rush out to buy one, however, be warned. The cost is just under $2,000.
That sounds like a lot, but test gear in this frequency range isn’t cheap. If you really need it, you’d probably have to pay at least as much …read more
I recently opened the mailbox to find a little device about the size of White Castle burger. It was an “Analog Discovery 2” from Digilent. It is hard to categorize exactly what it is. On the face of it, it is a USB scope and logic analyzer. But it is also a waveform generator, a DC power supply, a pattern generator, and a network analyzer.
I’ve looked at devices like this before. Some are better than others, but usually all the pieces don’t work well at the same time. That is, you can use the scope or you can use …read more
What do you get when you combine a direct digital synthesis (DDS) chip, a power detector, and an Arduino? [Brett Killion] did make that combination and wound up with a practical network analyzer.
The project uses an Analog Devices AD9851 DDS chip clocked at 180 MHz which will output a sine wave at any frequency from 0 Hz and 72 MHz. A Butterworth low pass filter processes the DDS signal and then feeds a two-transistor amplifier. The circuit will output about 0dBm into 50 ohms. The power detector is an Analog Devices AD8307 along with a 50-ohm input load. There …read more
