Design of a synchronous superregenerative receiver at 2.4 GHz

En aquest treball es descriu el procés de disseny i avaluació d'un receptor superregeneratiu per a la banda ISM de 2.4 GHz. El receptor utilitza un nou mode de funcionament en el qual el senyal d'extinció opera síncronament amb les dades rebudes, aconseguint així una notable millora en les prestacions globals del receptor.Postprint (author’s final draft

A direct-sequence spread-spectrum super-regenerative receiver

Current applications of the super-regenerative receiver use narrowband modulations. In this paper a new architecture that allows incoherent detection of spread-spectrum signals is presented. A pseudorandom code generator has been added to the original circuit. It is clocked by the quench oscillator and takes advantage of the characteristic broad reception bandwidth. CDMA can be achieved via ASK and FSK modulated signals with high simplicity in the RF stage as well as low power consumption.Peer ReviewedPostprint (published version

SNR measurement of superregenerative oscillators

© 2021 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes,creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.In this paper a method to measure the signal-to-noise ratio of superregenerative oscillators is presented. A spectrum analyzer can easily be coupled to a superregenerative oscillator without paying attention to possible loading effects. With just two measurements of the displayed power spectrum, in combination with the resolution bandwidth of the spectrum analyzer and the quench frequency of the oscillator, the signal-to-noise ratio is determined in a straightforward way. This is supported analytically with results from a frequency-domain analysis technique. Examples of the power displayed by a spectrum analyzer are given to provide insight into the explained procedure.Peer ReviewedPostprint (author's final draft

The nonlinear class-E amplifier: a case study of harmonic balance applied to switched circuits

Nonlinear switched circuits are usually analyzed in the time domain. The use of frequency-domain methods to analyze the steady-state of switched circuits is usually restricted to linear circuits and, although Volterra series approaches are applied to the distortion of nonlinear switched circuits, the use of harmonic balance (HB) methods in nonlinear switched circuits seems to be marginal if not discarded. In this paper, we analyze the nonlinear class-E amplifier with an ideal switch by means of the HB method. We show how the switching function may be carefully chosen to improve the accuracy of the solution. When the circuit achieves actual class-E operation, the method converges better and is more accurate than classical timedomain methods. We conclude that the HB method is an alternative to time-domain methods that can be used to analyze the class-E amplifier in its expected operation mode.Postprint (published version

A proof-of-concept superregenerative QPSK transceiver

In this paper we present a description and experimental verification of an HF-band proof-of-concept superregenerative transceiver for QPSK signals. We describe a simple implementation of an all-digital, FPGA-based, QPSK transmitter section. On the receiver side, the quench signal is generated in the same FPGA with a minimum of analog circuitry. As the main novelty, we present a simple synchronization scheme suitable for packetized transmissions.Peer ReviewedPostprint (author’s final draft

Signal and noise power spectra in superregenerative oscillators

© 2019 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.This paper presents a method to quantify noise in superregenerative oscillators. A frequency domain technique, originally intended to determine the signal response, can also be used to determine the noise response. This paper focuses on the procedure required to achieve this. Signal and noise spectra are obtained and their shape is compared. Finally, signal-to-noise ratio is computed for different quench signalsPeer ReviewedPostprint (author's final draft

Sub-nanosecond pulse filtering and amplification through firts-order controlled circuit instability

In this paper we investigate how to use controlled circuit instability in the filtering and amplification of narrow pulses. The basic circuit consists of a first-order RC network coupled to a negative resistance controlled by an external quench generator, which yields alternating periods of stability and instability. The study shows that when the circuit acts as a signal generator it can produce narrow exponential or Gaussian pulses, depending on the quench waveform applied. Included as a receiver front end, the circuit behaves as a highgain narrow-pulse filter. We also estimate the circuit parameters required to generate and receive sub-nanosecond pulses.Postprint (published version

A BPSK superregenerative receiver. Preliminary results

This paper describes a bit-synchronous superregenerative receiver suitable for BPSK demodulation. The output of the superregenerative oscillator (SRO), which reproduces the phase information of the input signal, is directly sampled by a D flip flop clocked by a signal derived from the quench waveform. Analytical background on the response of the SRO to a BPSK modulated input is presented. A PSpice macromodel of the receiver is also provided, allowing simulation in the linear and logarithmic modes of operation. Simulation results confirm the feasibility of the described approach. Finally, a proof-of-concept superregenerative receiver, capable of receiving a BPSK modulated carrier at 27 MHz with preliminary experimental results is presented. The measured sensitivity of this receiver is –99.5 dBm for a bit error rate of 10-3..Postprint (published version

Superregeneration revisited: from principles to current applications

© 2020 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.Wireless communications play a central role in our modern connected lives; at the same time, they constitute a very broad and deep area of research. The elements that make wireless communications possible are a transmitter, which sends information through electromagnetic waves; a medium that is able to transport these waves; and, finally, a receiver, which extracts the information from the-usually very small-amount of energy it is able to collect from the medium.Peer ReviewedPostprint (author's final draft

Circuits i sistemes lineals: col·lecció de problemes

2019/202