Agilent Technologies Switch/Measure Manual do Utilizador descarregar pdf (Página 21)

Tx and Rx band spurious

Theory in pictures

Tx band spurious is a measurement set that checks that the transmitter does

not put undesirable energy into the wrong parts of the Tx band (925–960 MHz

for E-GSM). This measurement reveals little more than the switching due to

modulation and wideband noise measurement, however, it is a swept measurement

with no time gating.

The Rx band spurious measurement deserves special attention. This is a measure

of how much energy the transmitter puts into the Rx band (880–915 MHz for E-

GSM) and the specification is extremely stringent. The reasons for this are clear;

potentially spurious from the transmitter can “jam” or “deafen” the receiver,

making the system useless. The Rx band spurious measurement deserves a special

explanation. See Figure 17.

Graphical view of limits and specifications

–104 dBm

+43 dBm

30 dB

Coupling

loss

Duplexer

The requirement corresponds to –128 dBm in 100 kHz RBW here. The signal leaking from the

transmitter to the receiver is approx 24 dB below the 'worst case' receiver signal of –104 dBm.

If it were much higher the transmitter would "deafen" the receiver.

Measurement Point

Requirement in Rx band:

–98 dBm in 100 kHz RBW

(for normal E-GSM900 BTS)

Figure 17. Theory of Rx band spurious

Freq (MHz)

= 942.5

Power

(dBc)

Example: E-GSM900, normal BTS

–98 dBm

880 915 925 960

–36 dBm

RBW = 100 KHz

RBW = 30 KHz

RBW = 100 KHz

RBW = 30 KHz

+ 1800 kHz

+ 6000 kHz

Channels and slots:

B, M, T.

Signal carrier (Tx band)

Multi-carrier (Rx band)

All slots on

Hopping:

Off

RBW:

30 kHz and 100 kHz

VBW:

3 x RBW (for Tx band)

1 x RBW (for Rx band)

Detection:

Peak

Sweep

Figure 18. Tx and Rx band spurious, BTS, limits

1 2 ... 16 17 18 19 20 21 22 23 24 25 26 ... 35 36

Comentários a estes Manuais

Sem comentários

Agilent Technologies Switch/Measure Manual do Utilizador Página 21

Comentários a estes Manuais

Manuais e produtos relacionados com Comutadores de rede Agilent Technologies Switch/Measure