The Content and Emphasis of (844) Basis of Signals and Circuits for Postgraduate Entrance Examination of Zhejiang University

Examination Outline of Fundamentals of Signals and Circuits (subject code 844)

Special reminder: This examination outline is only applicable to the postgraduate entrance examination in 2009. This course consists of four parts.

Sub-content, (-) signal and system part, accounting for 70 points; (2) Digital circuit, accounting for 40 points; (3) High frequency (RF) circuit, accounting for 40 points.

(1) signal system part

1. Recommended bibliography for postgraduate entrance examination

Signals and Systems, edited by Yu Huimin, Chemical Industry Press.

2. Basic requirements

Students are required to master the mathematical representation and signal analysis of decomposing general signals with basic signals (unit pulse, complex exponential signal, etc.). ); Master the common models of LTI system analysis (constant coefficient linear differential, difference equation, convolution representation, system function and simulation block diagram, etc.). ); Master the time domain method and transform domain method of signal and system analysis. Students are required to master some important concepts and basic properties of signal and system analysis, and master the basic operations of signal and system skillfully; Master the engineering applications and methods of signal and system concepts: modulation, sampling, filtering, extraction and interpolation; Master the principle and basic design method of discrete processing of continuous-time signals.

I. Basic concepts of signals and systems

(1) Basic signals of continuous time and discrete time

(2) signal operation and independent variable transformation

(3) Description and basic characteristics of the system

2. Time domain analysis. LTI system

Time domain analysis of (1) continuous-time LTI system: convolution integral, convolution property

(2) Time domain analysis of discrete-time LTI system: convolution sum and convolution properties.

(3) Zero input, zero state response and unit impulse response

(4) Basic properties of 4)LTI system

(5) Block diagram of LTI system expressed by differential equation and difference equation.

3. Frequency domain analysis of continuous-time signals and systems.

Characteristic function of (1) continuous-time LTI system

(2) Fourier series representation of continuous time period signals

(3) Continuous Fourier transform of aperiodic signals.

(4) Fourier transform characteristics

(5) Frequency response of continuous-time LTI system and frequency domain analysis of continuous-time LTI system.

(6) signal filtering and ideal low-pass filter

4. Frequency domain analysis of discrete time signals and systems.

Eigenfunction of (1) discrete-time LTI system

(2) Fourier series representation of discrete time periodic signals.

(3) Fourier transform of aperiodic discrete time signals

(4) Properties of discrete-time Fourier transform

(5) Frequency response of discrete-time LTI system and frequency domain analysis of discrete-time LTI system.

Verb (abbreviation for verb) sampling, modulation and communication system

Time domain sampling theorem of (1) continuous-time signal

(2) Undersampling and spectrum aliasing

(3) Time domain sampling theorem of discrete time signal, extraction and interpolation of discrete time signal.

(4) Discrete-time implementation of continuous-time LTI system

(5) sinusoidal carrier amplitude modulation and frequency division multiplexing of continuous-time signals.

(6) Pulse amplitude carrier modulation and time division multiplexing.

(7) sine carrier amplitude modulation of discrete-time signals.

Complex frequency domain analysis of intransitive verb signal and system

(1) Bilateral Laplace Transform, Convergence Domain and Zero Pole of Laplace Transform

(2) Laplace transform pairs of common signals

(3) Laplace transform properties

(4) Inverse Laplace transform

(5) Unilateral Laplace transform and its properties.

(6) Complex frequency domain analysis of system function and continuous-time LTI system.

Seven. Z-domain analysis of discrete-time signals and systems

(1) Definition of bilateral Z-transform, convergence domain of discrete-time Z-transform, zero-pole diagram.

(2)Z-transform characteristics

(3) Z-transform pairs of ordinary signals

(4) Inverse Z transform

(5) Unilateral Z-transform and its properties

(6) System function, Z-domain analysis of discrete-time LTI system.

(2) Digital circuit part

1. Recommended bibliography for postgraduate entrance examination

1.？ Fundamentals of digital electronics technology? The fifth edition is edited by Yan Shi, Higher Education Press.

2. Basic requirements

1. Master the methods of binary, decimal and their mutual conversion; Master the coding methods of 842 1 BCD code, 242 1 BCD code, remaining 3 codes and remaining 3 cyclic codes; Master the coding law of gray code and the conversion method between gray code and binary.

2. Master the basic operations, laws and rules of logic algebra; Master the standard form of logical function; Master the formula simplification method and Karnaugh map simplification method of logic function; Master various representations of logical functions and their transformations.

3. Familiar with the circuit composition and principle of CMOS integrated gate circuit and TTL integrated gate circuit; Master the physical meaning, input-output characteristics and input-output equivalent circuits of main parameters of CMOS circuit and TTL circuit; Master the matters needing attention in the use of integrated circuits.

4. Master the analysis and design of combinational logic circuits; Familiar with the competition and adventure of combinatorial logic.

5. Master the circuit function, logical relationship, expansion and application of combinational logic module circuits (priority encoder, decoder, data selector, adder and comparator).

6. Master the state transition truth table, state transition equation, excitation equation, state transition diagram and circuit symbols of various flip-flops (basic RS, clock RS, master-slave JK, edge JK, edge D, edge T); Master the dynamic characteristics of the trigger.

7. Master the analysis process of synchronous sequential circuits; Master the design of synchronous sequential circuit; Master the functions of registers, binary counters, decimal synchronous counters, reversible counters and shift registers, and master the applications of these devices; Understand the functions and applications of common asynchronous counters.

8. Master the method of using counters to realize common sequential circuits such as controllers and sequential signal generators.

9. Master the principle and application of digital-to-analog and analog-to-digital conversion.

10. Be familiar with the composition principle and application of semiconductor memory, and master the memory capacity expansion method.

1 1. main pulse waveform conversion circuit and pulse waveform generation circuit.

(3) RF circuit part

1. Recommended bibliography for postgraduate entrance examination

Chen Bangyuan, RF Communication Circuit (2nd Edition), Science Press.

2. Basic requirements

(1) Master the structural block diagram of the RF part of the transmitter and superheterodyne receiver, as well as the functions and main performance indicators of each component.

(2) Master the main basic knowledge of RF circuit design:

A) LC series-parallel resonant circuit: resonant frequency, resonant impedance, Q value, amplitude-frequency characteristics and phase-frequency characteristics.

B) impedance transformation: ideal transformer impedance transformation, reactance part access impedance transformation, L network impedance transformation and transmission line transformer impedance transformation.

C) Basic knowledge about noise: resistance thermal noise, noise figure, noise temperature and total noise figure of multilevel linear network.

D) The role of nonlinear devices in spectral shift: mainly grasp the characteristics of linear time-varying work.

(3) Understand the concepts of analog amplitude modulation (AM, DSB, SSB) and frequency modulation: expression, waveform,

Modulation index, spectrum structure, bandwidth, power.

(4) Main performance indexes of low noise amplifier.

(5) Main performance indicators of mixers, principle analysis of three main types of mixers (single tube, Gilbert multiplier and diode), and calculation of frequency conversion gain.

(6) Three basic conditions of feedback oscillator (starting vibration, balance and stability), LC oscillator circuit (mutual inductance coupling and three points), synchronous crystal oscillator circuit and varactor voltage-controlled oscillator circuit are analyzed.

(7) Basic knowledge of PLL: analysis methods of loop composition, loop equation, locking characteristics and tracking performance.

(8) Amplitude modulation and demodulation circuit:

A) Basic realization block diagram of amplitude modulation.

B) Principle circuit analysis of envelope detection and synchronous detection (product type and superposition type).

(9) FM demodulation circuit:

A) Analysis of varactor direct frequency modulation circuit.

B) Principle analysis of several common frequency discrimination circuits (slope frequency discrimination and quadrature frequency discrimination).

(10) Characteristics, current and voltage waveforms and efficiency of three common power amplifier circuits (Class A, Class B and Class C). A simple L-network will be used to convert the impedance between the amplifier and the load.