Loading in 5 sec....

Introduction to Space Systems and Spacecraft Design Space Systems DesignPowerPoint Presentation

Introduction to Space Systems and Spacecraft Design Space Systems Design

- 74 Views
- Uploaded on

Download Presentation
## PowerPoint Slideshow about ' Introduction to Space Systems and Spacecraft Design Space Systems Design' - carlotta-feddis

**An Image/Link below is provided (as is) to download presentation**

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.

- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript

Ref: SMAD Sections – 13 Communications Architecture

Introduction to Space Systems and Spacecraft Design

Space Systems Design

Dealing with large and small signal levels

Decibels -- powers of 10

Absolute power

PdB = 10Log10 (P2/P1)

Amplifier gain/loss

units - W

units – 1 W

units - dbW

PdB(dbW) = 10Log10 (P2(W)/1(W)

units - mW

units - dbm

units – 1 mW

PdB(dbm) = 10Log10 (P2(mW)/1(mW)

Introduction to Space Systems and Spacecraft Design

Space Systems Design

Dealing with large and small signal levels

Decibels -- powers of 10

PdB = 10Log10 (P2/P1)

PdB(dbW) = 10Log10 (P2(W)/1(W)

PdB(dbm) = 10Log10 (P2(mW)/1(mW)

3

Introduction to Space Systems and Spacecraft Design

Space Systems Design

Dealing with large and small signal levels

Decibels -- powers of 10

Output (dBW) = Input (dBW) + Gain(dB)

Output (W) = Input (W) x Gain

Add decibel

Multiply absolute values

4

Introduction to Space Systems and Spacecraft Design

Space Systems Design

Dealing with large and small signal levels

Decibels -- powers of 10

Output (dBW) = Input (dBW) + (- Loss(dB))

Output (W) = Input (W) x Loss

Add decibel

Component Loss (-Db)

Loss is value < 1.0

Multiply absolute values

5

Introduction to Space Systems and Spacecraft Design

Space Systems Design

P1

P2

Comparing Power Levels using Decibels

PdB = 10Log10 (P2/P1)

When (P2/P1) > 0 dB is positive

Amplifier – gain in power

Attenuation – loss in power

When (P2/P1) < 0 dB is negative

Let P1 = 4 watts

Let P2 = 8 watts

P2/P1 = 2 ratio

P(dB) = 3 dB

Let P1 = 8 watts

Let P2 = 4 watts

P2/P1 = 0.5 ratio

P(dB) = -3 dB

7

Introduction to Space Systems and Spacecraft Design

Space Systems Design

Absolute Power Levels using Decibels

PdBm = 10Log10 (P(mw)/1mw) reference to 1mw

= 10Log10 (1mw/1mw) = 0dBm

PdBw = 10Log10 (P(w)/1w) reference to 1w

= 10Log10 (8w/1w) = 9dBw

Every time it doubles, add 3dB

Every time it is 1/2, subtract 3dB

8

Introduction to Space Systems and Spacecraft Design

Space Systems Design

Powers greater >= 1 watt

0 dBw = 1 watt

3 dBw = 2 watts

6 dBw = 4 watts

9 dBw = 8 watts

10 dBw = 10 watts = 1 watt x 101

20 dBw = 100 watts = 1 watt x 102

30 dBw = 1000 watts = 1 watt x 103

100 dBw = 10 M watts = 1 watt x 1010

9

Introduction to Space Systems and Spacecraft Design

Space Systems Design

Powers greater <= 1 watt

0 dBm,= 1 milliwatt

-3 dBm = 0.5 milliwatts

-6 dBm = 0.25 milliwatts

-9 dBm = 0.125 milliwatts

-10 dBm = 0.100 milliwatt = 1 milliwatts x 10-1

-20 dBm = 0.010 milliwatts = 1 milliwatts x 10-2

-30 dBm = 0.001 milliwatts = 1 milliwatts x 10-3

= 0.001 milliwatts = 1 microwatt

10

Introduction to Space Systems and Spacecraft Design

Space Systems Design

11

Introduction to Space Systems and Spacecraft Design

Space Systems Design

Questions?

12

Introduction to Space Systems and Spacecraft Design

Space Systems Design

Download Presentation

Connecting to Server..