Super-regenerative receiver based on a barrier RF generator with OB<. Scheme, description

Free technical library

ENCYCLOPEDIA OF RADIO ELECTRONICS AND ELECTRICAL ENGINEERING
Free library / Schemes of radio-electronic and electrical devices

Super-regenerative receiver based on a barrier RF generator with OB. Encyclopedia of radio electronics and electrical engineering

Free technical library

Encyclopedia of radio electronics and electrical engineering / radio reception

Comments on the article

In works [1, 2], practical schemes of barrier RF generators are considered. At the same time, one more area of application of these generators was left without attention - as superregenerative detectors (receivers).

An RF generator operating in the intermittent generation mode can also serve as a superregenerative detector (receiver) if a number of requirements are met. Thus, using a barrier RF generator, it is possible to build a very simple super-regenerative receiver.

The discontinuous generation mode is most simply implemented using an integrating RC circuit in the power supply circuit of a barrier RF generator. The time constant of this RC circuit must be greater than the rise time of the RF oscillation amplitude in the generator circuit. Actually, this idea is not new, and has been repeatedly implemented.

For example, one of the schemes of a super-regenerative receiver using damping due to an RC circuit is considered in [3]. To build a super-regenerative receiver, one can, in principle, use almost any scheme of the barrier RF generator from those given in [1, 2].

The self-extinguishing mode due to the integrating RC circuit installed in the power circuit is possible due to the characteristic property of barrier generators. The fact is that at a relatively low voltage on the capacitor of the RC circuit, the generator does not work, and at the same time it presents a very high resistance to direct current. Therefore, the "inhibited" generator does not interfere with the charge of the capacitor through the resistance. When a certain voltage level is reached on the capacitor (approximately 0,6 V), the RF generator begins to generate. In this case, it represents a low enough resistance for direct current, the RC circuit capacitor is quickly discharged through the generating barrier generator. The voltage on the capacitor decreases, causing the generator to stop working again and go into "stuck" mode. This autosuperization process is periodically repeated. You can get acquainted with the features of the functioning of a receiver with self-extinguishing (autosuperization) in [4].

As shown by the author's experiments on germanium transistors, which are characterized by significant leakage currents, such a receiver cannot be made. Another important condition necessary for the possibility of autosuperization of the generator using an integrating circuit is the hysteresis in the transition from the "inhibited" state to the generating one, and vice versa.

Consider a practical scheme of a super-regenerative receiver (Fig. 1). The superregenerative detector is based on a barrier RF generator with OB [2]. Discontinuous generation (autosuperization) in this scheme is implemented using an RC circuit that includes C4 and R2 and R3 connected in series. The inductor L2 is necessary for RF decoupling, since the direct connection of C4 to the VT1 emitter makes generation impossible.

Super-regenerative receiver based on a barrier RF generator with OB. Schematic diagram of a super-regenerative receiver
Fig.1. Schematic diagram of a super-regenerative receiver

The frameless coil L1 contains 11 turns of wire with a diameter of approximately 0,8 mm. Winding is carried out turn to turn. A drill shank with a diameter of 5,5 mm is used as a mandrel.

The use of a small capacitor C1 and a resistor R1 with a resistance close to 50 ohms, as in [3], makes it possible to obtain an input resistance of 50 ohms.

The optimal mode of operation of the superregenerative detector (in particular, the average frequency of autosuperization) is achieved by selecting C4 and R3. The value of the capacitance C3 when the generator operates as a superregenerative detector must be much larger than is necessary for the occurrence of stable generation. Apparently, this phenomenon is associated with a decrease in the DC resistance (with an increase in capacitance C3) in the generation mode, and, possibly, with an increase in hysteresis phenomena with an increase in this capacitance.

The value of C3 is selected when setting up the receiver. The tuning technique practically does not differ from that given in [3]. The tuning range of the receiver is from 25 to 40 MHz.

Literature

Artemenko V. Barrier RF generators. - Radio amateur, 2001, N6, S.ZZ.
Artemenko V. Barrier LC generator with OB. - Radiomir, 2003, N9, p.37.
Artemenko V. Superregenerative receiver. - Radiomir, 2002, N10, C3.
Zherebtsov I.P. Radio engineering. - M.: Svyazizdat, 1963.

Author: V.Artemenko, UT5UDJ, Kiev; Publication: radioradar.net

See other articles Section radio reception.

Read and write useful comments on this article.

<< Back

Latest news of science and technology, new electronics:

Artificial leather for touch emulation 15.04.2024

In a modern technology world where distance is becoming increasingly commonplace, maintaining connection and a sense of closeness is important. Recent developments in artificial skin by German scientists from Saarland University represent a new era in virtual interactions. German researchers from Saarland University have developed ultra-thin films that can transmit the sensation of touch over a distance. This cutting-edge technology provides new opportunities for virtual communication, especially for those who find themselves far from their loved ones. The ultra-thin films developed by the researchers, just 50 micrometers thick, can be integrated into textiles and worn like a second skin. These films act as sensors that recognize tactile signals from mom or dad, and as actuators that transmit these movements to the baby. Parents' touch to the fabric activates sensors that react to pressure and deform the ultra-thin film. This ... >>

Petgugu Global cat litter 15.04.2024

Taking care of pets can often be a challenge, especially when it comes to keeping your home clean. A new interesting solution from the Petgugu Global startup has been presented, which will make life easier for cat owners and help them keep their home perfectly clean and tidy. Startup Petgugu Global has unveiled a unique cat toilet that can automatically flush feces, keeping your home clean and fresh. This innovative device is equipped with various smart sensors that monitor your pet's toilet activity and activate to automatically clean after use. The device connects to the sewer system and ensures efficient waste removal without the need for intervention from the owner. Additionally, the toilet has a large flushable storage capacity, making it ideal for multi-cat households. The Petgugu cat litter bowl is designed for use with water-soluble litters and offers a range of additional ... >>

The attractiveness of caring men 14.04.2024

The stereotype that women prefer "bad boys" has long been widespread. However, recent research conducted by British scientists from Monash University offers a new perspective on this issue. They looked at how women responded to men's emotional responsibility and willingness to help others. The study's findings could change our understanding of what makes men attractive to women. A study conducted by scientists from Monash University leads to new findings about men's attractiveness to women. In the experiment, women were shown photographs of men with brief stories about their behavior in various situations, including their reaction to an encounter with a homeless person. Some of the men ignored the homeless man, while others helped him, such as buying him food. A study found that men who showed empathy and kindness were more attractive to women compared to men who showed empathy and kindness. ... >>

Random news from the Archive

A new method for fast optical distance measurement 06.03.2018

The microresonator-based optical frequency comb enables extremely accurate distance measurements at a record speed of 100 million measurements per second. As a demonstration of how the new method works, researchers from the Karlsruhe Institute of Technology (KIT) and the Swiss Ecole Polytechnique Federale de Lausanne (EPFL) demonstrated the process of scanning the surface of a bullet flying at a speed of 160 meters per second, when In this case, the scanning accuracy was no worse than one micrometer at any given time. The new technology relies on a solitron optical frequency comb based on a microresonator fabricated on the surface of a silicon nitride chip. And further development of this technology will make it possible to create high-precision high-speed three-dimensional cameras and compact laser scanners of the LIDAR type.

One of the components of the new system are new light sources-on-a-chip, developed and created at EPFL University. The light from these sources serves to create an optical comb, when it enters the cavity of tiny circular resonators with non-linear optical characteristics, the continuous stream of light is converted into pulses called scattered Kerr solitrons, pulses that occupy a very wide band of the optical spectrum.

Note that this research group has been working with solitron optical frequency combs for quite a long time. Last year, scientists demonstrated the possibility of using such combs in broadband optical communications. An optical comb, in fact, consists of light that has several strictly defined wavelengths, i.e. the spectrum of this light resembles the teeth of a comb. If such light travels a certain distance, then the comb parameters will change, and comparing these parameters with the parameters of the reference comb will allow you to calculate the distance traveled by the light with high accuracy. And the more broadband an optical frequency comb is, the greater the distance measurement accuracy it can provide.

In a new method for measuring distance, the researchers used two optical chips that generate two identical frequency combs. The light from one chip was used to measure the distance, and the comb generated by the second chip served as a reference signal.

Other interesting news:

▪ Absolutely unbreakable screen for gadgets

▪ Ultra-compact 16-bit microcontroller MB90F455/456/457

▪ artificial vision

▪ 64 MP OmniVision sensor for smartphone cameras

▪ Nanosensor determines the freshness of meat

News feed of science and technology, new electronics

Interesting materials of the Free Technical Library:

▪ site section Electric motors. Article selection

▪ article Pouring mud. Popular expression

▪ article What color is the blood of a squid? Detailed answer

▪ article Pharmacist-analyst. Job description

▪ See Parallel Phone Call. Encyclopedia of radio electronics and electrical engineering

▪ article Power supply unit with digital indication of voltage and current, 220/0-30 volts 5 amperes. Encyclopedia of radio electronics and electrical engineering

Leave your comment on this article:

All languages of this page

Home page | Library | Articles | Website map | Site Reviews