Справочник Пользователя для Lectrosonics Inc D4T

5

D4R Receiver

The receiver is essentially a mirror image of the trans-

mitter. The incoming RF signal is converted back into 

the baseband signal that was generated in the trans-

mitter, and the FPGA decodes the signal to generate 

the four audio channels in digital and analog formats 

as they appeared at the transmitter inputs.
Diversity reception is employed to suppress multipath 

dropouts, followed by SAW filters in the front-end to 

attenuate signals above and below the passband. The 

FPGA monitors and adjusts the level of the incoming

RF signal to increase the dynamic range capabilities of 

the receiver.

From the IQ demodulator through the filters, amplifier 

and baseband ADC, the signal path and processing 

is the reverse of that in the transmitter. Decoding in 

the FPGA regenerates the original digital and analog 

audio signals and delivers them to the output stages.
The FPGA also delivers a signal to a DAC and amplifer 

for monitoring with headphones. The headphone out-

put follows the receiver selected on the front panel.

FILTER

FILTER

LOW
NOISE
AMP

LOW
NOISE
AMP

OSC

900 MHz

RF

DEMOD

RF

DEMOD

DIGITAL 

BASEBAND 

DECODER 

and

DIVERSITY 

SYSTEM

24-bit D/A

(analog)

AES/EBU 

OUT

(digital)

24-bit D/A

(analog)

AES/EBU 

OUT

(digital)

24-bit D/A

(analog)

24-bit D/A

(analog)

TA3F 

OUTPUTS

1

2

3

4