UTC L8115

LINEAR INTEGRATED CIRCUIT

QW-R123-005,B

* Stripline Elements

* C1

* L2

* C3

10nF

Q1

*L1

C2

10nF

47nF

47nF

33k

4.7nF

LNB Downfeed

R2

2k

Rcal

Fin

Lov

Csub

HB

LB

G1

D1

G2

D2

D3

Gnd

Cnb1

Vpol

Vcc

UTC L8115

SSOP20(150mil)

Vcc

G3

Cnb2

N/C

NC

NC

SSOP20(150mil) Applications circuit

1

The following block diagram shows the main section of an LNB designed for use with the Astra series of

satellites. The UTC L8115 is the core bias and control element of this circuit. The UTC provides the negative rail,

FET bias control, polarisation switch control, tone detection and band switching with the minimum of external

components. Compared to other discrete component solutions the UTC circuit reduces component count and

overall size required.

Single Universal LNB Block Diagram

UTC L8115

Regulator

Vertical

Antenna

Gain Stage

GaAs/HEMTFET

2

Polarity Switch &Tone Detect Input

Gain Stage

GaAs/HEMTFET

3

Mixer

Gain Stage

ASTRA

Universal Band

10.70GHz-12.75 GHz

Horizontal

Antenna

1

Gain Stage

GaAs/HEMTFET

Band

Switch

Output

Local Osc 1

9.75 GHz - Low Band

Local Osc 2

10.6GHz - High Band

IF down feed

950-2050 MHz - Low Band

1100 - 2150 MHz - High Band

+

Tone detection and band switching is provided on the UTC L8115 devices. The following diagrams describes

how this feature operates in an LNB and the external components required. The presence or absence of a 22kHz