Application Note
page 7 of 33
V1.7
2022-08-01
XENSIV™ BGT60LTR11AIP shield
60 GHz radar system platform
Hardware description
38.4 MHz
quartz
EEPROM
LED1
LED2
2
1.8V or 3.3V
LDO
1.5V_RF
1.5V_PLL
SPI
IRQ
TDet
PDet
IFI
IFQ
Castellated Holes
5
3.3V
V
in
V
in
1.5V_RF
1.5V_RF
V
in
2
C
o
n
n
ect
o
rs
t
o
R
a
d
a
r
B
a
seb
o
a
rd
MC
U
7
B
G
T
6
0
LT
R
1
1
A
IP
MMI
C
Figure 4
Block diagram of the BGT60LTR11AIP shield
The block diagram in Figure 4 depicts the configuration of the shield. When the shield is plugged into the Radar
Baseboard MCU7, the MMIC
’s supplies are initially deactivated. Only the
EEPROM is powered. The MCU reads the
content of the EEPROM’s memory to determine which
shield is plugged into the connectors.
MMIC’s supplies are
activated only when the shield has been correctly identified.
Communication with the MMIC is mainly performed via a Serial Peripheral Interface (SPI). The BGT_RTSN allows
the MCU to perform a hardware reset of the MMIC. The BGT_SELECT and BGT_RTSN lines of the SPI should be
pulled up with 10 kΩ resistors.
The interrupt request (IRQ) line can be used to trigger the MCU when new data
needs to be fetched.
3.2
BGT60LTR11AIP MMIC
The BGT60LTR11AIP MMIC (Figure 5) serves as the main element on the BGT60LTR11AIP shield. The MMIC has
one transmit antenna and one receive antenna integrated into the package. The package dimensions are 6.7 mm
(± 0.1 mm) x 3.3 mm (± 0.1 mm) x 0.56 mm (± 0.05 mm), as illustrated in Figure 6 and Figure 7.
The MMIC has an integrated Voltage Controlled Oscillator (VCO) and Phase Locked Loop (PLL) for high-
frequency signal generation. The transmit section consists of a Medium Power Amplifier (MPA) with
configurable output power, which can be controlled via the SPI.
The chip features a low-noise quadrature receiver stage. The receiver uses a Low Noise Amplifier (LNA) in front
of a quadrature homodyne down-conversion mixer in order to provide excellent receiver sensitivity. Derived from
the internal VCO signal, an RC Poly-Phase Filter (PPF) generates quadrature LO signals for the quadrature mixer.
The Analog Base Band (ABB) unit consists of an integrated sample and hold circuit for low-power duty-cycled
operation followed by an externally configurable high-pass filter, a Variable Gain Amplifier (VGA) stage and a low-
pass filter.
