2FSK Signal Generator Based on AT89C51 Microcontroller

2013 ◽  
Vol 722 ◽  
pp. 260-264
Author(s):  
Xue Fei Gao ◽  
Yong Li An
Keyword(s):  
Second Order ◽  
Signal Generator ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Low Pass ◽  
Output Side ◽  
Base Band ◽  
Band Signal

In order to simplify the devices used for generating the 2FSK signal, a 2FSK signal generator based on AT89C51 microcontroller is proposed in this paper. A digital base band signal is inputted to the microcontroller through one of I/O ports. Then microcontrollers program is executed, which are designed for generating PWM signals according to the sine waveforms corresponding with 2FSK signals required. Consequently, an appropriate PWM signal is outputted from another I/O port. This PWM signal is sent into a simple second order passive low-pass filter, and the 2FSK signal can be obtained on the output side of the filter. The 2FSK signal generator makes full use of the resources of the microcontroller, and as a result, it is simple, easy to use, economical and reliable.

Gm-C low-pass-filter designed for a Zero-IF base-band demodulator

2007 ◽  
Author(s):  
H. Barthelemy ◽  
S. Bourdel ◽  
N. Dehaese ◽  
J. Gaubert ◽  
G. Bas
Keyword(s):  
Pass Filter ◽  
Low Pass Filter ◽  
Low Pass ◽  
Base Band

Study of a second order low pass filter based on hybrid SETMOS

2013 ◽  
Author(s):  
Li Cai ◽  
Qiang Kang ◽  
Dang Yuan Shi
Keyword(s):  
Second Order ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Low Pass

The Design of Ideal Positioning Servo System

2015 ◽  
Vol 816 ◽  
pp. 132-139
Author(s):  
Ľubica Miková ◽  
Alexander Gmiterko ◽  
Michal Kelemen
Keyword(s):  
Frequency Characteristic ◽  
Pid Controller ◽  
Transfer Functions ◽  
Servo System ◽  
Second Order ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Low Pass ◽  
Degree Of Stability

The paper deals with the design of an ideal positioning servo system. To achieve this aim, we will derive transfer functions of the PID controller and the second-order low-pass filter while using typical fault frequencies for PID controller with a low pass filter. Consequently, an overall frequency characteristic of the open servo system will be depicted. This characteristic will be further used to determine the amplitude and phase safety, which determine the degree of stability system.

Chatter alleviation for a class of second-order under-actuated mechanical systems with matched and mismatched disturbances

2016 ◽  
Vol 23 (3) ◽  
pp. 458-468
Author(s):  
Jinjin Shi ◽  
Jinxiang Wang ◽  
Fangfa Fu
Keyword(s):  
Sliding Mode ◽  
Mechanical Systems ◽  
Design Procedure ◽  
Second Order ◽  
Control Input ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Sliding Surfaces ◽  
Low Pass ◽  
Mismatched Disturbances

The chattering phenomenon and a system with both matched and mismatched disturbances are the major difficulties in sliding mode control design. This paper presents an effective design procedure to alleviate these two difficulties for a class of second-order under-actuated mechanical systems. In the proposed design, new hierarchical sliding surfaces are designed and a modified disturbance observer is utilized to estimate the lumped disturbance which is a linear combination of the matched and mismatched disturbances. The chatter in control input is filtered out by an integrator, which acts as a low-pass filter. The asymptotic stabilities of the entire sliding surfaces are guaranteed. A design study considering lateral control of a vehicle with matched and mismatched disturbances demonstrates the effectiveness of the proposed design.

HISTORY AND PROGRESS OF THE TOW–THOMAS BI-QUADRATIC FILTER PART I: GENERATION AND OP AMP REALIZATIONS

2008 ◽  
Vol 17 (01) ◽  
pp. 33-54 ◽  
Author(s):  
AHMED M. SOLIMAN
Keyword(s):  
Second Order ◽  
Spice Simulation ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Circuit Performance ◽  
High Q ◽  
Op Amp ◽  
Compensation Methods ◽  
Low Pass ◽  
History Of

The history of Tow–Thomas second-order filter is reviewed. Two alternative generation methods of the Tow–Thomas filter are discussed. The first is a generation method from the second-order passive RLC filter and the second is from the multiple feedbacks inverting low-pass filter using a single op amp. Several forms of the circuit are briefly reviewed. Passive and active compensation methods to improve the circuit performance for high-Q designs are summarized. Spice simulation results are included.

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