Table of Contents
Advertisement
No. 2D730-148E*O
4.1.3
RCB
(1)
Outline
The RCB (Receive Control Board) controls the front-end section, AD-converts the
reception signals, and performs receive beam forming.
(2)
Descriptions of functions and operations
The RCB includes the following functions.
(a)
Front-end section scan control:
RTC (Real Time Controller) block
The transmission/reception
in the front-end section is controlled according to control
information from the RM. The RTC block consists of an FPGA (Field Programmable
Gate Array, programmable
IC) and SRAM. The sequencer set in the FPGA transmits
data to each block of the front-end section according to the scan control information
to be stored in the register in the FPGA and SRAM.
(b)
AD conversion and receive beam forming:
RXBF (Receive Beam Former) block
The reception signals obtained for every ch are AD-converted
with a sampling
frequency of 40 MHz and a quantification
precision of 10 bits. The required reception
delay is applied to each converted signal and addition is pet-formed.
This block
consists of 12 ASlCs (RXBF ASICs).
(c)
Analog control signal generation:
Analog Control block
The analog control signals required in the front-end section (listed below) are
generated.
They are obtained by performing
DA conversion for the digital codes
output from the RTC.
l
VTGC (time gain compensation)
This signal controls the preamplifier gain depending
on the depth of reception.
This signal is input to the RXAR ASIC (preamplifier
IC) in the TR board.
l
VAAC (antialias control)
This signal is used to control the signal bandwidth
before the AD conversion.
This
signal controls the cutoff frequency of the low-pass filter (antialias filter) in the
RXAR ASIC.
l
TXV (transmit voltage control)
This signal controls the transmission
pulse voltage.
The signal is input to the TR
PWB via the power supply unit.
l
VMD (voltage for midpoint bias)
This signal controls the bias point of the reception echo signal line between the TR
board and RC board (between the RXAR ASIC and RXBF ASIC). The signal is
input to the RXAR ASIC.
4-13
Advertisement
Table of Contents
