Mini Project- Radio Receiver Design 1. Project Overview Project Day 1 Brief Project Day 1 Guidance Project Day 2 Brief Project Preparation Radio Receivers Architecture of a radio receiver Building blocks of a radio receiver Principal performance parameters of a radio receiver Electronic design of selected parts of a radio receiver Radio Wave Propagation Please see: Mini Projects - Introductory presentation. Mini Projects - E-Log. Mini Projects - Standard Grading Criteria. Mini Projects - Reflection. Section 1. Results of laboratory measurements such as spectrum analyser plots, gain measurements, selectivity curves, bandwidth measurements.
Analysis and discussions of results, contrasting between AM and FM receivers. Day 2 Expected Outcomes for the day: To have designed and built a superhet receiver using a combination of pre-built modules and modules designed by the student. To have measured the overall performance of the receiver in 2 different frequency bands for test signals and off-air broadcast signals. Critical evaluation of performance compared to specification given. Assessment criteria: Block diagram of superhet radio receiver designs.
Measurement of overall response of radio receivers in two different bands using modulated test signals at the antenna input with varying modulating frequency. Evaluation of performance in relation to design specification. Assessment of radio receiver performance in three different bands using off-air signals.
Facilitator Guidance key ideas to draw out from students : Day 1: Measurements of communication building blocks - use of signal generators and other test equipment Day 2: Operation of a superhet receiver, gain, selectivity, frequency conversion, track tuning of RF and L. Section 2. To have received at least 3 different MF broadcast signals. Assessment criteria: Schematic diagrams of the various radio receivers and the tuned RF amplifier stage. Results of laboratory measurements such as gain measurements, selectivity curves, bandwidth measurements.
Analysis and discussions of results. Page 4 of 34 5. Section 3. Project Day 1 Guidance Application Notes on components and circuit boards These notes are circuit ideas that you can use but you will need to work out how to use them and also calculate some component values. The IF amplifier circuit boards have been custom-built and some of the electronic components used in this mini project have been ordered specially, so the number of spares available may be very limited.
Your progress may be delayed or you may lose marks if you 'blow up' destroy a circuit board or an electronic device that has been ordered specially. The audio amplifier Start by building an audio amplifier for your radio receiver. A suitable circuit is shown in Fig. Although the LM is an audio amplifier IC, it is capable of oscillating at radio frequencies if the circuit layout or supply decoupling are not good enough. The circuit in Fig. These should all be grounded via very short wires approx. It must be located close to IC1. The AM IF amplifier board.
Page 5 of 34 6. Fig 2 a. These boards have been set to various different centre frequencies and are marked with frequency codes A - F. Note which one you are using and keep the same IF board for Day 2. If the signal is AC coupled into this pin, a resistor to ground is required. As the gate current of the FET is insignificant, this resistor can be relatively high, e. In pin.
Alternatively, Q1 can be used as an amplifier by leaving the L. In pin disconnected. When using Q1 as an amplifier, grounding the L. In pin will increase the gain why? When measuring the gain of the IF amplifier, find out how much difference grounding this pin makes. The IF Out pin can be used to attach a "times 10" 'scope probe for gain measurements. Do not use a "times 1" probe and do not attach a wire to this pin as this is likely to cause instability unwanted oscillation.
When testing the IF amplifier, do not over-drive the input otherwise the gain measurement will not be valid. If the IF output level is more than about 1 V p-p, reduce the input signal level to avoid over-driving the amplifier. Find the centre frequency then measure the -6dB bandwidth and the dB bandwidth. The Audio Out pin is the demodulated AM output. It also contains a negative-going d.
Page 6 of 34 7. This reduces the gain of Q1 on strong signals. R7 and C6 form a low-pass filter with a cut-off frequency of approx. Instead of using two different d.
It is important to a. The recommended Local Oscillator L. Do not short-circuit either of the output pins 4 or 5 to ground as this will destroy the chip. Design, construction and testing of a varicap-tuned HF RF amplifier This is a major part of the Day 1 mini project and at least half the time should be allowed for this task.
Page 7 of 34 8. The objective is to design, build and test an RF amplifier for an HF receiver that covers the "49 metre", "41 metre" and "31 metre" international broadcast bands. You will need to find out the frequencies of these bands and design your amplifier accordingly. You also have some Zetex ZCB varicap diodes available for tuning.
This will simplify the varicap tuning arrangement. Fig 4. Nevertheless, it may be necessary to omit C2 to reduce the gain. Varicap diode tuning Varicap tuning can be added to replace C1. The following type of varicap diode is available and the typical characteristics are shown below. The 'back-to-back' configuration is preferred because it offers better strong signal handling. It is better not to use tuning voltages below 2 V but if this is necessary to achieve the required tuning range, the 'back-to-back' configuration should be used.
It is also better not to use tuning voltages above 12 V, to avoid the need for a separate tuning voltage supply. Page 8 of 34 9. Select a suitable type of varicap diode and a suitable circuit configuration, then update your schematic diagram. The tuning voltage potentiometer should be a linear type, not logarithmic. Output buffering The tuned amplifier load RL needs to be relatively high e. It should also be noted that even with a 'times 10' 'scope probe, adds a capacitive load of about 13 pF, which will prevent the tuned amplifier from tuning up to its highest design frequency.
In order to drive a lower impedance load, such as the 1. Suggested layout on Solderless Connection Board SCB Although Solderless Connection Boards SCB are not generally suitable for constructing radio frequency electronic circuits, it is possible to use this type of construction for this mini project provided a suitable layout is used, interconnecting wires are kept as short as possible and attention is paid to decoupling power supply rails. The photo below shows the recommended SCB layout. Page 10 of 34 Section 4.
Radio receiver design - Wikipedia
To have evaluated the performance of the various stages. To have received an HF radio broadcast signal that originates outside the UK. Construct the amplifier and measure its characteristics, e. Using a 50 cm length of wire as an antenna, receive an HF radio broadcast signal that originates outside the UK and attempt to identify the source. Evaluate the shortcomings of the receiver for this type of signal. Page 11 of 34 Section 5. Project Preparation Preparation Session 3hrs : Laboratory session, familiarisation with RF test equipment and measurements.
Due to the limited number of spectrum analysers, some students will need to do part 2 before part 1. B Set the RF signal generator to give the following output: Frequency: MHz, amplitude mV RMS, modulation, FM 75 kHz deviation at 10 kHz using internal modulation source Set the spectrum analyser to display the above signal in such a way that the sidebands are visible and save a trace to your own USB flash drive or you personal files area on Studynet and include it in your E-log.
Measurement of bandpass response of tuned circuit. Using a ferrite rod antenna with tuning capacitor, couple an unmodulated signal from the RF signal generator into the 2-turn coupling winding on the ferrite rod. Connect an oscilloscope across the black and pink wires with ground to black, using a "Times 10" probe.
Set the variable capacitor to maximum capacitance and find the resonant frequency. Make measurements at a suitable number of frequencies and plot a frequency response curve down to the dB points. Find the -3dB bandwidth and hence the 'Q' factor. Repeat with the variable capacitor set to minimum capacitance. A 'crystal set' radio receiver.
Connect a simple AM detector consisting only of a diode to the pink and black wires black is ground so that the demodulated output is fed to a crystal earphone. Connect approx. Tune the variable capacitor and find an AM broadcast signal that can be heard in the earphone. Page 12 of 34 Project Introduction 1. Cohort: DCE2 [B. Eng] 2. Project Title: Radio receiver design and evaluation 3. Project Summary: This project involves working from a specification for the performance of a radio receiver and making laboratory measurements on various building blocks. Introductory Lecture 2hrs Content: 1 General Project area: radio receivers.
Preparation Session 3hrs : Laboratory session, familiarisation with RF test equipment and measurements Page 13 of 34 Radio Receivers Every type of radio communication system requires a transmitter and a receiver. In this section, the principles of some typical radio receivers will be studied. For types of modulation that require a linear receiver e.
Hence a bandpass filter with a sharp roll-off is normally required. In practice, such a filter can generally only be designed to operate at a fixed frequency and it is not generally practicable to make such a filter tuneable. GPS satellite navigation or 60 kHz MSF time code , most receivers need to be able to tune to a range of frequencies, usually controlled by a frequency synthesiser and microcontroller.
Page 14 of 34 Selectivity is achieved by bandpass filtering at the frequency of the received signal. The TRF architecture is seldom used because of practical difficulties in achieving sufficient selectivity and of tuning the receiver if it is required to cover a range of frequencies. Another practical difficulty with a TRF is that all the gain is at the same frequency, which can result in problems of instability, i.
Radio Receiver Design
In a superhet receiver, the received signal is fed to a mixer. The other input of the mixer is driven by a local oscillator L. The mixer generates sum and difference frequencies. See the Shortwave Radio Kit below! MTM Scientific, Inc. Recently I discovered a pile of old issues of Elektuur magazine in our local university library. A very good explanation is provided here. This radio is in daily use. The emitter current to the PA transistor Q2 is limited by emitter resistor R5 and the power amp base-emitter junction is used as the detector.
It is necessary to drill out the matrix board in order thal it may take the transistor holder, If desired, TR2 and TR3 can also be fitted in Iranslstor holders, whereupon it becomes to a number Of transistors for Opera- tion in the receiver, a little off topic, but here are the pictures of my two transistor reflex receiver. This is a great receiver. If these experiments don't show the benefits of measurement, then I'm afraid nothing will. The unit shown Figs. Using a very high gain transistor for both radio and audio frequencies, Bazian's design had the loudest output of any one-transistor radio I've ever heard.
I think that a superhet with two transistors, or a good regenerative receiver will perform better than this reflex superhet. If a standard tool is not to hand a substitute can be made from a short When using a Darlington pair as an AM detector, the collector of the first left transistor should be connected to the supply rail, in stead of connecting it to the collector of the second right transistor. I don't normally offer this to beginners, but build the receiver the same way except with the "tank" circuit fed into the base of the transistor.
The Receivers I. The audio recovered at inductor L is rather strong comparing to ZN and free from oscillations. Subminiature Reflex Receivers. Where I don't want to slog through in a half-understood language, I use Google's translation page.
RADIO RECEIVERS DESIGN
Circuit Diagram Of Am Radio Receiver Can you please suggest a possible circuit diagram with components mentioned for an AM receiver which will be able to receive requencies between. Weymouth 6-transistor receiver. One Transistor Pocket Radio. I'm sure Clive Sinclair would have been delighted if such an IC was around when his keyring Micro Matic two transistor AM reflex receivers were being developed.
Simple AM Radio Receiver. In this case RF and Audio. The one transistor AM radio receiver is something all whippersnappers try out when starting out on the royal road to radio building. As more stations took to the air, however, TRF became the circuit of choice. Here I am going for minimalist. Golden Submitted to the Department of Electrical Engineering and Computer Science in Partial Fulfillment of the Requirements for the Degree of Master of Engineering in Electrical Engineering and Computer Science at the Massachusetts Institute of Technology When it comes to making an FM receiver it's always thought to be a complex design, however the one transistor simple FM receiver circuit explained here simply shows that it isn't the case after all.
A receiver, or integrated amplifier, is even more involved in its role, as it has sour Moved Permanently. By Alvin Mason Designing and constructing a one-transistor pocket receiver is a challenge to any experimenter. Back in the day, Radio had so called P Kits. Shortwave Radio Experiments. It doesn't need an antenna, gives speaker reception of local AM broadcast stations and also receives amateurs talking on the metre band.
I was hesitant to put a battery in it because I am unsure of it's electrical viability and I did not want to damage it. In our case, it resorts to transistor Q1's base-emitter input capacitance and NPO-type ceramic capacitor C2 to effect the correct impedance transformation and phase shift necessary for regeneration to take place.
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GARC Regenerative Radio Project Aim This is a simple, yet high performance regen radio that can be built with parts that are readily available, mostly from Jaycar and at a modest cost. The term reflex means a circuit is amplifying two different but related signals at the same. A photo-transistor is simply a transistor that "turns on" when IR hits it. Condition is Used. I chose this name because I believe the circuit is just about the simplest, fully functional superheterodyne receiver one can construct with just a handful of parts. Schematic diagram of the Simple Superhet AM broadcast band receiver.
The clue that a set has a transistor detector is the lack of a detector diode and the presence of a transistor in the circuit between the final IF transformer and the volume control. The second transistor is used as an AF amplifier. A tutorial on the principles of AM radio receiver design. I had discovered in an earlier receiver that this topology requires reduced regeneration adjustment as it is tuned, due to increasing Vackar feedback at low frequencies being counteracted by increasing varactor losses at low frequencies Ref.
A typical circuit diagram for a Crystal Set Radio is given below where inductor or coil L1 is tuned by variable capacitor VC1 to the transmitter frequency. Read honest and unbiased product reviews from our users. The basis of my radio is this circuit. Reflex Receivers. Firstly it act as an RF amplifier. This is a regenerative reflex receiver and you may have issues with unwanted feedback, even with the regen control all the way down like I did. It does somewhat work but pops too much to really call it working.
Single tube or transistor circuits are quite common and widely used. It would be unusual to find this power level in a receiver, even the LO would be more like 10 or 20 mW. Use the following formula for determining the frequency. As in the reflex receivers of the s, a single active component here, a germanium transistor amplifies both R. Please ask any questions. The reflex receiver was a variation in which the detected audio was passed through one or more of the RF stages for further amplification. Reflexing makes this set comparable to a 7 tube set of the time by using the same tube as an RF amplifier and AF amplifier.
The Q1 gives required amplification transistor's quiescent current 1mA, voltage of transistor's collector around 3V; A high-Z ear phone might work, but i use an Audio Amplifier for playing aroud, gain x Common Emitter reflex I. One thing I noticed with Rick Anderson's receiver above is that the 0. The set employed three transistors.
In these days I began to use the transistor having ft over 1GHz. It's based on the principle of the ZN only it can handle higher coverage. L1 provides negative mutual inductance between the two tuned circuits to maintain a constant bandwidth of approximately 12KHz across the entire to Xtaflex 40m VXO regenerative receiver - Michael J.
This range covers the 49 m and the 41 m shortwave bands in which many European stations broadcast. A reflex radio receiver, occasionally called a reflectional receiver, is a radio receiver design in which the same amplifier is used to amplify the high-frequency radio signal RF and low-frequency audio sound signal AF. The next level of detail. The unit shown in Figs. Diode D1, capacitor C2 and resistor R1 does the detection of the picked signal.
This am regenerative receiver circuit project use four 1. My previous 6 transistor receiver was more bulky, requiring 12V. The An unusual AM reflex T.
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Strong stations will provide plenty of volume into a crystal earphone or an external amplifier. Here is the circuit diagram of a simple radio that uses one transistor and few other passive components. Use the one transistor to amplify both RF and audio. It's basically a normal transistor that has it's BE diode exposed to incoming light. BCB receiver without coils. A capacitor 26 is connected between the collector of transistor 22 and ground to stabilize the operation of transistor It drives a speaker to room volume on local stations and it's reasonably selective.
At first I glance it appeared to be part of the low pass pi filter. There are a number of schematics on the Internet. This is the old 0-V-2 design. This is a compact three transistor regenerative general coverage receiver with fixed feedback. Radio receiver circuit diagram pdf. Here are plans for building a shortwave radio receiver using 3 transistors, a simple homemade coil, an Air Variable Capacitor and some common electrical parts. From the coupling coil L3 the signal goes to the base of the transistor T1. Although more complex and finicky, reflex circuits reduced tube and power requirements.
As can be seen in the schematic diagram in figure Three basic types of supper-regenerative receiver were used for radio control of models:- The hard valve receiver, the soft valve receiver and the transistor based receiver with circuits appropriate to single channel, galloping ghost and reed operation. Results 1 - 16 of Most of single transistor FM radio receiver circuits I found on the internet dont. It was a dream to have a good looking case for their Three transistor FM receiver needed modifications.
This was also a reflex receiver and it had the famous coil. The circuit may be used as a signal booster with VHF receivers whose front end suffers from low sensitivity such as many valved and army surplus types. And this is a first cut at a two transistor superhet receiver. In an inverting amplifier the voltage enters the chip through leg two and comes out of the chip at leg six. RI controls the bias on both transistors. The second or quench oscillation typically operates at frequencies above the audio range, e. One thing you cannot use this circuit for is as a Doppler radar module.
The ability to tune List - Gives frequencies used in many tube radios. Simple one-transistor receiver 4. The last time I built a superhet receiver was when I was in college. It has served me well the past 2 years. Reflex circuit As mentioned before, some sets have an extra audio amplifier stage between the volume control and the driver stage. Set your FM receiver for a clear, blank station. I am very pleased to report that I have finally built a radio receiver that is good enough that I can enjoyably use it!
Reflex circuits were very popular in years past but not used much today. With the "reflex" approach the first amplifier was used as both a regenerative RF amplifier and first audio amp, with the second tube as the audio output amp. This arrangement is discussed later. Performance is equivalent to a 3 transistor receiver, giving very good volume in a crystal earphone. This am regenerative receiver circuit works over mile range around km with a four-foot antenna.
JFETs operate at input voltages less than 0. In fig. Automotive Infotainment and Telematics Minimize menu. After the merger of the two companies in , ST continued to be the main radio IC supplier of SiriusXM, which counts now over 30 million service subscribers. ST is very proud to have contributed to the most successful story in the Digital Radio market developing seven generations of radio ICs based on state-of-art CMOS technology to deliver features of increasing complexity with continuous improvement in power performance.
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