beautypg.com

3 if local oscillator, 1 specifications, Figure 5-5. if lo block diagram – Comtech EF Data KST-12000 User Manual

Page 96

background image

KST-12000 Ku-Band Satellite Terminal

Revision 4

Theory of Operation

MN/KST12000.IOM

5.3 IF Local Oscillator

The IFLO contains a Voltage Controlled Oscillator (VCO), loop filter, and a divide down
chain.

The loop tracking voltage is sent to the M&C board, where it is monitored along with the
lock detect fault.

Refer to Figure 5-5 for a block diagram of the IFLO.

5.3.1 Specifications

Input

10 MHz square wave, CMOS levels

Output

1150 MHz (2 each), 2300 MHz (2 each)

Connectors SMA
Output Impedance

50

Output level

+7 dBm (-4 dBm, U/C Synth Reference)



IF L O C A L O S C IL L AT O R

1 0 M H z R E F E R E N C E

D /C S Y N T H R E F

D / C IF L O

F ILT E R

U /C IF L O

S M A F E M A L E

C M O S L E V E L S

S Q U A R E W AV E

2 3 0 0 M H z

S M A F E M A L E

+ 7 d B m

2 3 0 0 M H z

S M A F E M A L E

+ 7 d B m

11 5 0 M H z

S M A F E M A L E

+ 7 d B m

11 5 0 M H z

S M A F E M A L E

+ 7 d B m

L O O P

F I L T E R

P H

U /C S Y N T H R E F

A S E

D E T E C T

V C O

D IV ID E
D O W N

C H A IN

Figure 5-5. IF LO Block Diagram

5–12