5.3 Transmitter

• Introduction
• 5.3.1 Transmitter identification
• 5.3.2 Transmitter power
• 5.3.3 Transmitter antenna pointing
• 5.3.4 Antenna patterns identification
• 5.3.5 Emission characteristics

Introduction

It can be the ILT or the VLT as illustrated in Figure 146.

 

 

It consists in 4 panels (Figure 147); Transmitter identification, antenna pointing, antenna patterns identification, emission characteristics. 

 

 

5.3.1 Transmitter identification

This is the same panel as in section 5.2.1 so that transmitter characteristics can be imported/exported from/to the library to/from the workspace and you can freely chose a name and a description.

5.3.2 Transmitter power

In SEAMCAT, the transmitter power (P) is expressed as conducted power in dBm, including feeder loss. The antenna peak gain (G) is expressed in dBi.

Consequently, the power calculated by SEAMCAT at the antenna output is the effective isotropic radiated power (e.i.r.p.) expressed in dBm:

e.i.r.p (dBm) = P (dBm)+G (dBi)

If the transmitter power is defined as e.i.r.p (dBm) or e.r.p (dBm), the conducted power (P), including feeder loss, can be calculated as follows:
P (dBm)= e.i.r.p (dBm)-G (dBi);
P (dBm)= e.r.p (dBm)-G (dBi)+2.15.

If the antenna gain is not known, it should be assumed zero, then:
P (dBm)= e.i.r.p (dBm);
P (dBm)= e.r.p (dBm)+2.15.
Note that G (dBi)= G (dBd)+2.15.

Example 1: P_t= 50 dBm (conducted transmitter power), L_f (feeder loss) = 2 dB, G_ant (antenna gain) = 15 dBi
SEAMCAT settings should be: Power (dBm) = 50 - 2 = 48, Antenna Peak Gain (dBi) = 15
e.i.r.p (dBm) calculated by SEAMCAT= P (dBm)+G (dBi) = 48 + 15 = 63 dBm

Example 2: e.i.r.p = 63 dBm, G_ant = 15 dBi, feeder loss in not needed
SEAMCAT settings should be: Power (dBm) = 63 - 15 = 48, Antenna Peak Gain (dBi) = 15
e.i.r.p (dBm) calculated by SEAMCAT= P (dBm)+G (dBi) = 48 + 15 = 63 dBm

Example 3: e.r.p = 60.85 dBm, G_ant = 12.85 dBd, feeder loss in not needed
SEAMCAT settings should be: Power (dBm)= 60.85 - 12.85 = 48, Antenna Peak Gain (dBi) = 12.85 + 2.15 = 15
e.i.r.p (dBm) calculated by SEAMCAT= P (dBm)+G (dBi) = 48 + 15 = 63 dBm

Example 4: e.i.r.p = 63 dBm, no other information available
SEAMCAT settings should be: Power (dBm) = 63, Antenna Peak Gain (dBi) = 0
e.i.r.p (dBm) calculated by SEAMCAT= P (dBm)+G (dBi) = 63 + 0 = 63 dBm

Example 5: e.r.p = 60.85 dBm, no other information available
SEAMCAT settings should be: Power (dBm) = 60.85, Antenna Peak Gain (dBi) = 2.15
e.i.r.p (dBm) calculated by SEAMCAT= P (dBm)+G (dBi) = 60.85 + 2.15 = 63 dBm

5.3.3 Transmitter antenna pointing

This is the same panel as in section 5.2.1 so that transmitter characteristics can be imported/exported from/to the library to/from the workspace and you can freely chose a name and a description.

5.3.4 Antenna patterns identification

It contains all information relative to the antenna radiation pattern. It is similar to the receiver antenna patterns identification (Section 5.2.3). 

5.3.5 Emission characteristics

This panel consists in setting of the emission characteristics of your generic system.