A 150 foot length of coax has a loss of 2.2 dB per 100 ft. The connectors on each end add 0.2 dB of loss each. The transmit antenna provides 10.2 dB of gain, and free space attenuates the signal by 135 dB. If the receiving antenna requires a minimum signal of -70 dBm, what is the required transmitter power in dBm and watts?

Introductory Circuit Analysis (13th Edition)
13th Edition
ISBN:9780133923605
Author:Robert L. Boylestad
Publisher:Robert L. Boylestad
Chapter1: Introduction
Section: Chapter Questions
Problem 1P: Visit your local library (at school or home) and describe the extent to which it provides literature...
icon
Related questions
icon
Concept explainers
Question

#3

**Problem:**

A 150-foot length of coax has a loss of 2.2 dB per 100 ft. The connectors on each end add 0.2 dB of loss each. The transmit antenna provides 10.2 dB of gain, and free space attenuates the signal by 135 dB. If the receiving antenna requires a minimum signal of -70 dBm, what is the required transmitter power in dBm and watts?

**Solution Approach:**

1. **Calculate total coax loss:**
   - Loss for 150 ft = \( \left(\frac{150}{100}\right) \times 2.2 \, \text{dB} = 3.3 \, \text{dB} \)

2. **Calculate total connector loss:**
   - Each end = 0.2 dB
   - Total connector loss = \( 2 \times 0.2 \, \text{dB} = 0.4 \, \text{dB} \)

3. **Determine overall losses and gains:**
   - Total loss = coax loss + connector loss + free space loss = \( 3.3 + 0.4 + 135 \, \text{dB} \)
   - Total gain from antenna = 10.2 dB

4. **Calculate net loss:**
   - Net loss = total loss - antenna gain = \( (3.3 + 0.4 + 135) - 10.2 = 128.5 \, \text{dB} \)

5. **Determine required transmitter power:**
   - Minimum received signal = -70 dBm
   - Required transmitter power = minimum received signal + net loss = \( -70 + 128.5 = 58.5 \, \text{dBm} \)

6. **Convert dBm to watts:**
   - \( P \, \text{(watts)} = 10^{\left(\frac{58.5}{10}\right)} \times 10^{-3} \)
   - \( P \approx 0.7079 \, \text{watts} \)

**Conclusion:**

The required transmitter power is approximately 58.5 dBm, or 0.7079 watts.
Transcribed Image Text:**Problem:** A 150-foot length of coax has a loss of 2.2 dB per 100 ft. The connectors on each end add 0.2 dB of loss each. The transmit antenna provides 10.2 dB of gain, and free space attenuates the signal by 135 dB. If the receiving antenna requires a minimum signal of -70 dBm, what is the required transmitter power in dBm and watts? **Solution Approach:** 1. **Calculate total coax loss:** - Loss for 150 ft = \( \left(\frac{150}{100}\right) \times 2.2 \, \text{dB} = 3.3 \, \text{dB} \) 2. **Calculate total connector loss:** - Each end = 0.2 dB - Total connector loss = \( 2 \times 0.2 \, \text{dB} = 0.4 \, \text{dB} \) 3. **Determine overall losses and gains:** - Total loss = coax loss + connector loss + free space loss = \( 3.3 + 0.4 + 135 \, \text{dB} \) - Total gain from antenna = 10.2 dB 4. **Calculate net loss:** - Net loss = total loss - antenna gain = \( (3.3 + 0.4 + 135) - 10.2 = 128.5 \, \text{dB} \) 5. **Determine required transmitter power:** - Minimum received signal = -70 dBm - Required transmitter power = minimum received signal + net loss = \( -70 + 128.5 = 58.5 \, \text{dBm} \) 6. **Convert dBm to watts:** - \( P \, \text{(watts)} = 10^{\left(\frac{58.5}{10}\right)} \times 10^{-3} \) - \( P \approx 0.7079 \, \text{watts} \) **Conclusion:** The required transmitter power is approximately 58.5 dBm, or 0.7079 watts.
Expert Solution
Step 1: Define transmitted power.

The quantity of energy radiated by a transmitter is known as transmitted power. It is often expressed in terms of watts or decibels (dBm) in relation to one watt. The performance and range of a wireless communication system are significantly influenced by transmitted power. The kind of antenna being used, the frequency of the signal, and the transmitter's power output are just a few variables that can have an impact on the amount of transmitted power.

steps

Step by step

Solved in 3 steps with 5 images

Blurred answer
Knowledge Booster
Antenna Characteristics
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, electrical-engineering and related others by exploring similar questions and additional content below.
Similar questions
Recommended textbooks for you
Introductory Circuit Analysis (13th Edition)
Introductory Circuit Analysis (13th Edition)
Electrical Engineering
ISBN:
9780133923605
Author:
Robert L. Boylestad
Publisher:
PEARSON
Delmar's Standard Textbook Of Electricity
Delmar's Standard Textbook Of Electricity
Electrical Engineering
ISBN:
9781337900348
Author:
Stephen L. Herman
Publisher:
Cengage Learning
Programmable Logic Controllers
Programmable Logic Controllers
Electrical Engineering
ISBN:
9780073373843
Author:
Frank D. Petruzella
Publisher:
McGraw-Hill Education
Fundamentals of Electric Circuits
Fundamentals of Electric Circuits
Electrical Engineering
ISBN:
9780078028229
Author:
Charles K Alexander, Matthew Sadiku
Publisher:
McGraw-Hill Education
Electric Circuits. (11th Edition)
Electric Circuits. (11th Edition)
Electrical Engineering
ISBN:
9780134746968
Author:
James W. Nilsson, Susan Riedel
Publisher:
PEARSON
Engineering Electromagnetics
Engineering Electromagnetics
Electrical Engineering
ISBN:
9780078028151
Author:
Hayt, William H. (william Hart), Jr, BUCK, John A.
Publisher:
Mcgraw-hill Education,