Topic Attenuators Subject Communication Engineering Theory 34042 IV

Topic: Attenuators Subject: Communication Engineering Theory (34042) IV Semester Diploma in Electronics & Communication Engineering. Slides By : Mr. Gopalakrishnan. B. , Lecturer ECE -Selection Grade, Govt. Polytechnic College for Women, Pondicherry – 605008.

Attenuators Course Objectives • To know what is Attenuator • What is it made up of? • Types ? • Commonly used types • Resistor Attenuators. • What about Volume Control in a Audio Player.

Attenuators • Learning Outcomes • Choose the Attenuator for an Application. • How to make a 10 d. B , 20 d. B, 40 d. B attenuator. • Practical Applications. • Identify the types practically. • Identify the load. • Solving the problems for T &

Attenuators • Attenuator ? Design of T & ∏ Symmetrical Attenuator. • Attenuators - Resistive networks used to introduce a known amount of loss. • Made by Resistors or Capacitors. • Symmetrical Type - Network Parameters Affected. • Asymmetrical Type – Network parameters are not affected. • Resistor Attenuators have all elements Resistors.

T - Attenuators Look Like letter T • R 1 = R 0(N-1)/(N+1) ; R 2 = R 0(2 x. N/N 2 -1) • N = Antilog 10(D/20) in Nepers ; D in decibels(d. B). • Attenuators can be Resistive or Capacitive.

∏ - Attenuators Look Like letter ∏ • R 1 = R 0((N 2 -1)/2 N)) ; R 2 = R 0(N+1)/(N-1) • N = Antilog 10(D/20) in Nepers ; D in decibels(d. B). • Applications - Matching , Power & Volume , High frequency,

Questions Design a π-type attenuator to give 20 d. B attenuation and to have a characteristic impedance of 600 ohms. 1. The Value of N in Nepers is for 20 d. B attenuation is a. 1 b. 10 c. 100 d. 1000 2. The value of R 1 for a. 3000 Ω b. 2970 Ω c. 3030 Ω d. 2940 Ω

Questions Continued Design a π-type attenuator to give 20 d. B attenuation and to have a characteristic impedance of 600 ohms. 3. The value of R 2 for a. 733. 11 Ω b. 733. 22 Ω c. 733. 33 Ω d. 733. 44 Ω 4. What is the main component in Symmetrical Attenuator? a. Resistors b. Inductors c. Battery d. Switch

Check Your Answers Design a π-type attenuator to give 20 d. B attenuation and to have a characteristic impedance of 600 ohms. 1. The Value of N in Nepers is for 20 d. B attenuation is b. 10 2. The value of R 1 for b. 2970 Ω 3. The value of R 2 for c. 733. 33 Ω 4. What is the main component in Symmetrical Attenuator? a. Resistors. Scores: 2 fair, above 2 is good, 4 is very good. THANKS…