Assignment

Guangdong Institute of Education

BTECCenter

Program: Electrical/Electronic Engineering (Electronic)

Unit Title: Electronics

Unit No: 12 Assignment Title: Analyze and improve the wireless receiver(2)

Assignment No.: 1202

Issue Date: 4.10

Submission Deadline: 6.10

Assessor/Tutor: Sa Yang

Internal Verifier: Ricky Zhang

Student:

Student’s Reg. No:

NOTES TO STUDENTS

Check carefully the submission date and the instructions given with the assignment. Late assignments will not be accepted.

Ensure that you give yourself enough time to complete the assignment by the due date.

Do not leave things such as printing to the last minute – excuses of this nature will not be accepted for failure to hand-in the work on time.

You must take responsibility for managing your own time effectively.

If you are unable to hand in your assignment on time and have valid reasons such as illness, you may apply (in writing) for an extension.

When you refer to the work of other authors in your assignment, you must practice citation by following Harvard System for Referencing.

If you are caught plagiarizing, you could have your grade reduced to zero, or at worst, you could be excluded from the course.

STUDENT’S DECLARATION:

I confirm that this is all my own work.

Student Signature:

ASSESSMENT

Outcome/
Grade / Criteria/
Descriptors / Evidence /

Feedback

/

Assess

/ IV
Pass Assessment
Investigate
signals and noise / 1.1 use logarithmic units and reference levels to express measured values of gain and attenuation / ※formula for calculating is right
※the calculation results right
1.2 describe the types and sources of noise in electronic systems and methods of noise reduction / ※detailed analysis of noise sources
※noise reduction method is reasonable
1.3 explain the concepts used to describe the effects of noise and make practical measurements / ※accurate description of the definition
※ the calculation results right
※noise tests is true and right
Investigate oscillators / 4.1 describe the circuit conditions and the methods used to achieve sinusoidal oscillation / ※formulas for conditionsare right
※detailed methods are listed
※the kind of oscillation selected is right
4.2 build and evaluate a sine wave oscillator to a given specification / ※the circuit designed is reasonable
※the evaluation method is right
4.3 explain the advantages of crystal-controlled oscillator circuits / ※the explanation of advantages is detail and reasonable

Grading Assessment

M1identify and apply strategies to find appropriate solutions

/ An effective approach to study and research has been applied. / ※the strategies to design the oscillator is definite and reasonable
※ cite correctly referencing to fully conform to Harvard system
M2 select/design and apply appropriate methods/techniques / Relevant theories and techniques have been applied. / ※apply the simulation software to analyze the circuit
※grasp the experimental means to solve the circuit problem
M3
present and communicate appropriate findings / A range of methods of presentation have been used and technical language has been accurately used. / ※present and express these tasks in a fluent language
※format of this assignment is correct
※make less grammar error
D1
use critical reflection to evaluate own work and justify valid conclusion / Conclusions have been arrived at through synthesis of ideas and have been justified. / ※conclusions have been arrived at through synthesis of ideas
※the validity of results has been evaluated using defined criteria
D2
take responsibility for managing and organizing activities / Autonomy/independence has been demonstrated. / ※the oscillator circuit is designed independently
D3 demonstrate convergent/lateral/ creative thinking / Innovation and creative thought have been applied. / ※receptiveness to new ideas is evident when design the oscillator circuit
※innovation and creative thought have been applied when analyze the effects of crystal oscillator.
Assessor’s additional comments
Assessor’s signature:
Student’s Feedback
Student’s signature:

Notes:

Assignment Description

Scenario:

Now, you are a product development engineer of an electronics company. The company received a business, which is to improve the wireless receiver customer provided to reach the customer’s technical requirements. As a development engineer, your task is to analyze the wireless receiver circuits, then, improve the circuits to meet customer requirements at the lowest cost.You should provide ananalysis report as detail on the following problems.

Tasks:

1. (Pass Criterion 1.1) Use logarithmic units and reference levels to express measured values of gain and attenuation.In assignment 1, you have analyzed the audio-frequency input stage amplifier of the wireless receiver. Please use logarithmic units to express the values of voltage gain, current gain and power gain of this circuit. Suppose the amplitude of input voltage is 10mV, use reference levelsto express the values of output voltage and output current.

Tips: You have already obtained the performance parameters of this circuit in task 3, assignment 1.

2. (Pass Criterion 1.2)Describe the types and sources of noise in electronic systems and methods of noise reduction.Many kindsof noise which influence the operation performance of the receiver exist here. Please describe the types and sources of noise in the wireless receiver and methods about how to reduce noise. Which noise effect is most significant in this kind of device?

3.(Pass Criterion 1.3)Explain the concepts used to describe the effects of noise and make practical measurements. We often use noise temperature to express the effects of noise and noise figure to express the ability that system deal with noise. Please explain these concepts in your words. The audio-frequency input stage amplifier of this wireless receiver generates a noise power, referred to its input terminals, of 3uW. If the signal applied to the amplifier input is -10dBm with signal-to-noise ratio of 30 dB, calculate the signal figure of this amplifier. Do some practical measurementsof environment noise with sound level meter and list your measurement steps.

4.(Pass Criterion 4.1)Describe the circuit conditions and the methods used to achieve sinusoidal oscillation. In the wireless receiver, there exist many oscillators. Please describe the circuit conditions and the methods used to achieve sinusoidal oscillation. If we want a sinusoidal signal of 1KHz, which kind of oscillator should be chosen?

5. (Pass Criterion 4.2)Build and evaluate a sine wave oscillator to a given specification. An oscillator in the wireless receiverwhich acted as a local oscillatorwas damaged of over-current. The frequency of this oscillator is in the range of 500KHz--1MHz and its output voltage is larger than 1V. Please build a Colpits oscillator to replace it. Evaluate the performance of the oscillator you designed.

6.(Pass Criterion 4.3)Explain the advantages of crystal-controlled oscillator circuits.The wirelessreceiver has a crystal-controlled oscillator whose circuit is showed in figure 2.1. Please list the advantages of this circuit and explain the reasons.

Fig. 2.1 Crystal-controlled oscillator

Reference:

Books:

Author / Publish Year / Title (including sub-title) / Edition / Place of Publication / Publisher

Journal articles:

Author / Publish Year / Title (including sub-title) / Journal title / Volume Number / Pages

Internet resource:

Author / Publish Year / Title (including sub-title) / URL

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