Receive Data Chain - Analog Devices ADRV9005 Reference Manual

Reference Manual
RECEIVER/OBSERVATION RECEIVER SIGNAL CHAIN
such as the ORx gain. When the ADRV9001 device is in control of the observation channel, it must configure the observation channel properly
without any user intervention.
Figure 147 shows that each receiver has three inputs. One is the ILB input dedicated for receiving ILB signal. The others are Rx1A/Rx2A and
Rx1B/Rx2B inputs. One is configured to receive RF signals and the other to receive ELB signals. The ADRV9001 has an option to select the
main receive port (either port A or port B) during initialization. For example, if port B is selected as the main receive port, then port A is used
to receive ELB signals. Furthermore, the ADRV9001 provides dynamic port switching capability to switch the receive ports (either port A or port
B) on the fly. This is mainly designed to accommodate applications that have limitations on operating frequency range of the RF Balun. In this
case, multiple Baluns can be used to cover the entire frequency range (30 MHz to 6 GHz) supported by the ADRV9001. To support seamless
switch between multiple Baluns that cover different frequency ranges, the dynamic port switching feature allows the use of both port A and B
as main data receiver channels while switching between the two ports at run-time based on the carrier frequency ranges defined for each port.
Note that once this feature is enabled, it applies to both receive channels, which means there is no support for switching port A/B on Rx1 but
using fixed port on Rx2. In addition, ELB cannot be enabled in this case.
Due to the support of a wide range of applications, the user interaction with the receiver signal chain is mainly done through configuration
profiles. Based on the channel profile, which includes key parameters such as bandwidth, sample rate, and AGC settings, initial calibration
is performed in the device to set up the receive chain properly. When DPD is performed internally in the device, the switch between receiver
and observation channel is fully determined without user interaction. When the DPD is performed externally by the baseband processor, the
baseband processor owns the entire ORx channel. Make sure that there is no conflict between the DPD operations and the transmitter tracking
calibrations in the device.
In the ADRV9001, a specialized "Monitor mode" allows the device to autonomously poll a region of the spectrum for the presence of a signal,
while in a low power state. In this mode, the chip continuously cycles through sleep-detect-sleep states controlled by an internal state machine.
Save power by ensuring the sleep duty cycle is greater than the "detect" duty cycle. In the "sleep" state, the chip is in a minimal power
consumption configuration, where few functions are enabled. After a predetermined period, the chip enters the "detect" state. In this state, the
chip enables a receiver and performs a signal detect over a bandwidth and at a receiver LO frequency determined by the user. If a signal is
detected, the "Monitor Mode" state machine exits its cycle and normal signal reception resumes. If no signal is detected, the chip resumes
its sleep-detect-sleep cycle. The sleep-detect duty cycle and signal detection method are user-programmable, and are set before enabling
"Monitor Mode." For more details, see the
The ADRV9001 provides various levels of power control. Power scaling is performed on individual analog signal path blocks to trade off power
and performance. In addition, enabling and disabling various blocks in the TDD receive and transmit frames to reduce power are customized, at
the expense of receive/transmit, or transmit/receive turnaround time. For more details, see the
The following sections provide topical information on:
Receive Data Chain: Describes how the analog and digital components are used at the different stages of the receiver chain to convert RF
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signals to bits at the desired sample rate for further baseband processing.
Analog Front-End Components
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Digital Front End Components: Discusses each major DFE component and its functionality.
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Receive Data Chain API Programming: Outlines the API programming capabilities of the receiver data chain for user interactions.
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RECEIVE DATA CHAIN

The ADRV9001 supports both NB and WB applications in a common design.
data chain, which is composed of AFE and DFE. The AFE includes a front-end attenuator, which controls the received RF signal level, mixer
for RF to baseband (or IF) down conversion, low-pass filter, and a pair of HP and LP ADCs. The LPF has a programmable -3dB bandwidth
from about 6.7 MHz to 40 MHz, depending on the profile. Its configuration and filter characteristics are automatically tuned internally to achieve
optimal performance for different applications. In principle, the AFE design is based on the WB architecture with a very high dynamic range to
absorb both the desired signal and interference without distortion. Therefore, in such a design, very little channelization, or blocker filtering is
needed through LPF because the HP and LP ADC can simultaneously absorb weak signals and large blockers. The blocker suppression and
channelization are then achieved efficiently in the digital signal path. After ADC, the digital output signal is further processed through multiple
stages in DFE.
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Power Saving and Monitor Mode
: Discusses each major AFE component and its functionality.
section.
Power Saving and Monitor Mode
Figure 148 describes the block diagram of the entire receiver
ADRV9001
section.
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