Specifications

EASTAR UHP-1000 SERIES SATELLITE ROUTER

INSTALLATION AND OPERATION MANUAL, V. 2.3

(SW VERSION 2.2.9)

TX 1000 MHz (L-band)

+BUC_LO (13050 MHz)

14050 MHz (Ku-band)

-LNB_LO (10000 MHz)

RX 1000 MHz (L-band)

11000 MHz (Ku-band)

-SAT_LO (3050 MHz)

Figure 15 Graphical example of the entire signal path via satellite and antenna

system

If the satellite signal frequency is known in Ku-band, e.g. 11 215 140 000 Hz (or 11.215140

GHz or 11 215 140 KHz), then knowing the LO frequency of the installed LNB (e.g. 9.75

GHz) one can calculate the value in the L-band.

11 215 140 000 – 9 750 000 000 = 1 465 140 000 HZ OR 1 465 140 KHZ

2.5.2 Searching the satellite carrier

Any LNB features LO frequency deviation from its declared value. This deviation has a

certain constant component plus component caused by temperature changes. Constant

component may vary slowly due to LNB components aging. Deviation due to temperature

(winter/summer) usually lies within the bandwidth of ±500 KHz. Constant component is

usually not in excess of 500 KHz to either side but there are samples with deviation of up to

1,500 KHz. PLL LNB with 10 MHz internal reference fall also under this effect but their

deviation range is substantially lower – just a few KHz. Accuracy of PLL LNB with external

reference frequency depends on the accuracy of the router reference oscillator.

The LO inaccuracy leads to the fact that the real frequency of the carrier coming to the

router differs from that at which we expect this carrier.

Respectively, the router should search for the carrier in a certain bandwidth close to the

selected value. The search algorithm is as follows:

F(base) - Search_BW

F(base) + Search_BW

Start again

Limit

reached

Figure 16 Satellite carrier search algorithm

Search is carried out within a certain user-defined bandwidth. If the carrier is not found

upon reaching the search limit the search is repeated. Search bandwidth should be wider

than the possible frequency offset caused by deviation in LO LNB. But the wider the range

the longer is the complete search cycle.