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first Experiment: SPECTRUAL ANALYSIS OF THE SIGNALS
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Objectives
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To understand the concepts of time and frequency domains as applied to a waveform.
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Practical of Experiment
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In this practical you will investigate how the waveshape in the time domain effect the spectrum in the frequency domain. This is an important relationship to understand in order to be able to adjust how much frequency spectrum is occupied by a signal
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Second Experiment: EFFECT OF FILTERING & NOISE OF THE SPECTRUM
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Objectives
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To examine the effects of filtering on waveshape and bandwidth restriction
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Practical of Experiment
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Effect of Filtering on Waveshape and Spectrum.
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Third Experiment: AMPLITUDE MODULATION DOUBLE SIDEBAND WITH FULL CARRIER
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Objectives
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To understand the concept of multiplying two sinusoidal waveforms.
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Practical of Experiment
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In this practical you will investigate how two sinusoidal signals are multiplied together to produce a modulated signal. The two signals are generated on the workboard.
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Fourth Experiment:DEMODULATION WITH AN ENVELOPE DETECTOR AND WITH A PRODUCT DETECTOR
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Objectives
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To investigate demodulation of an amplitude modulated signal using an envelope detector and subsequent filtering.
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Practical of Experiment
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Demodulation is the reverse process to modulation. In this case it takes the modulated signal of a carrier and two sidebands and extracts the modulating signal from it. In this instance this can be done very simply.
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Fifth Experiment: FREQUENCY MODULATION USING AN IQ MODULATOR
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Objectives
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To appreciate that a frequency modulated signal can be produced using an IQ modulator and the advantages of this method.
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Practical of Experiment
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In this practical you will generate frequency modulation (FM) by using an IQ modulator. Since there is a good method of generating FM by using direct modulation of a voltage controlled oscillator |
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Sixth Experiment: DEMODULATION OF FM USING A PHASE LOCKED LOOP
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Objectives
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In the Practical you will see how the PLL operates as a demodulator
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Practical of Experiment
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The FM generator that you will use in this Practical is the VCO that you have already used modulated by the function generator. The PLL is made from the local oscillator, which is also a VCO, and multipliers used as a phase detector. A loop filter and a post detection filter complete the demodulator)
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Seventh Experiment: Ultrasonic GENERATING SSB WITH AN IQ MODULATOR
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Objectives
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To appreciate that a single sideband suppressed carrier signal may be produced using phasing, rather than filtering, methods.
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Practical of Experiment
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1The generation of an SSB signal can be achieved by a number of methods. They fall into two categories: filtering out the unwanted sideband with a bandpass filter, or by using phase to cancel it out
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Eighth Experiment: SAMPLING AND TIME DIVISION MULTIPLEXING
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Objectives
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In this practical you will investigate time division multiplexing using two A/D converters and a single D/A converter.
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Practical of Experiment
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1Two analogue signals: one a sinusoid and the other a variable dc voltage are fed into the two A/D converters. The microprocessor samples the two alternatively at 20 kHz. The multiplexed signal is passed to a D/A and you can see it on the oscilloscope.
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Ninth Experiment: ALIASINGE EFFECTS OF ALIASING
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Objectives
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In this practical you will investigate the effect of sampling an analogue signal at sample rates near to and below its frequency
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Practical of Experiment
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Aliasing can be a significant problem in any sampling system and can result in completely misleading results. The lowest rate that can be used to sample a signal is twice the frequency of the signal you are trying to sample. Even then the results may not be satisfactory
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