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Following several annoying issues with Jekyll, I decided to switch to Hugo.
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Announcements
Gönül's website is awesome
Impressed by the awesome new website of co-author Gönül Demir, I started relooking this blog.
RF Design
Power Amplifiers
Nonlinear impedance (draft)
A comprehensive analysis of nonlinear impedance effects in power amplifiers, including transistor output impedance behavior and gain compression.
Site
Announcements
New co-authors
This site had first an only author. Following the joining of co-author Gönul Demir, I updated the title to reflect the introduction of guest authors.
Oscillators
Circuit Design
The fine art of (not) doing oscillators
Practical insights and common pitfalls in oscillator circuit design, with real-world examples and solutions.
Analog Design
Operational Amplifiers
A (not so) gentle introduction to operational amplifiers.
A comprehensive guide to understanding operational amplifiers, their characteristics, configurations, and practical applications in analog circuits.
Operational Amplifiers
Filters
Analog Design
Simple calculations for active bandpass filter with finite GBW operational amplifier.
Simple calculations for active bandpass filters taking into account the finite GBW of operational amplifiers.
RF Design
Power Amplifiers
Backoff calculations.
Determining the backoff needed between the used power and the maximum power to amplify multi-carrier signals can be tricky. Here is a study of this topic.
DSP
Signal Processing
Hilbert transform demo.
The discrete Hilbert transform seems rather mysterious, but it is mainly a way to add a 90° phase shift to a signal which can be explained by an Excel spreadsheet.
Impedance Matching
LC Networks
LC ladder impedance matching.
A comprehensive guide to LC ladder impedance matching networks, with interactive calculation tools.
Operational Amplifiers
Differential Amplifiers
Equations for terminating a differential amplifier in single-ended input.
A few years ago, I had to terminate a differential amplifier in single-ended input. Analog Devices AN-0990 gives equations for that. Unfortunately, there are an inaccuracy in these equations.
Operational Amplifiers
Stability
On stability of capacitive loaded op-amps.
Operational amplifiers are often use with capacitive loads, typically to split a rail, but stability can be tricky.
Couplers
IQ Modulators
RF Design
IQ modulator and quadrature coupler sign issues.
On IQ quadrature sign conventions in branchline couplers, originally published on Microwaves 101.
Transmission Lines
Microstrip
Microstrip formulas comparison.
A comparison of microstrip characteristic impedance calculation formulas.
Components
Capacitors
MLCC voltage dependence.
On the voltage dependence of MLCC capacitors, originally published on Microwaves 101.
S-parameters
Transmission Lines
Calculation of characteristic impedance from S parameters.
Suppose one wants to measure or simulate the characteristic impedance of something similar to a transmission line. This can be for example a 75 Ω coax cable or a via structure on HFSS. The characteristic impedance can be calculated form its measured or simulated S parameters references to 50 Ω.
Software
QGIS
Tools
Export QGIS maps and terrain height data to Forsk Atoll.
Forsk Atoll antenna planning software is not so hard to use when a suitable map and terrain height data is available for import into Atoll. However such ready to use data is rather hard to find and finding such data is the top question asked in the comments of most Atoll tutorials.
Antennas
Group Delay
On group delay of antennas.
Following a very interesting discussion on LinkedIn, an investigation into antenna group delay.
Power Combiners
Coaxial
RF Design
Design of a coaxial power combiner with low-impedance inputs and increased isolation.
Unpublished article about coaxial power combiners with low-impedance inputs and increased isolation.
S-parameters
Network Analysis
Transfer S parameters.
Originally published on Microwaves 101, an explanation of transfer S-parameters and their applications.
Amplifiers
Miller Effect
Miller effect and solutions.
Originally published on Microwaves 101, a comprehensive explanation of the Miller effect in electronics.
RFID
NFC
Circuit Design
RFID coils should not be grounded.
While putting a solid ground plane in a good practice in most PCBs, RFID coils should not have ground planes below them.
RFID
Antennas
Why RFID antennas should not be called antennas ?
A friend of mine told me that he was looking for an "expert antenna engineer" to design RFID antennas, but are RFID coils really antennas ?