UG-1828
Preliminary Technical Data
Rev. PrC | Page 140 of 338
TRANSMITTER/RECEIVER/OBSERVATION RECEIVER SIGNAL CHAIN CALIBRATIONS
In ADRV9001, to achieve optimal performance, an ARM performs calibrations which can be classified into two categories: initial
calibrations performed at the initialization time before the device is operational; and tracking calibrations performed regularly while the
device is operational.
Initial calibrations are considered as a part of the device initialization, which moves the device from “STANDBY” state to
“CALIBRATED” state to prepare for transmit/receive operations. Tracking calibrations are performed regularly on-the-fly while the
device is operational to track the changes such as attenuation, temperature and so on. As discussed in the Rx Signal Chain section of this
User Guide, ADRV9001 includes 2 transmitters and 2 receivers. for each receiver, besides acting as a primary data channel for receiving
RF signals, it could also serve as an observation channel, which receives transmit signals through loopback paths. The observation
channel could be controlled fully by the user or internally controlled by the device for some transmitter initial and tracking calibrations.
Note for some systems such as FDD 2T2R, the transmitter tracking calibrations requiring loopback paths could not be performed since
the observation channel is not available. Refer to ADRV9001 Example Use Cases section for more details.
Most initial calibrations use internally generated tones or wideband signals for calibration, which need user to satisfy external system
requirements. This topic will be discussed in more details in later sections. Different from initial calibrations, tracking calibrations usually
use the real-time traffic data for calibration. Therefore, tracking calibrations are transparent to users which do not require any user
intervention. Both initial and tracking calibrations are scheduled and performed by the ADRV9001 ARM.
INITIAL CALIBRATIONS
There are three types of initial calibrations, which are:
•
System (non-channel related) initial calibrations
•
Initial calibrations for RF PLLs to calibrate the RF PLL for very fast frequency hopping mode (currently not available),
•
Aux PLL initial calibration (currently not available).
•
Tx initial calibrations
•
Quadrature Error Correction (QEC),
•
Local Oscillator (LO) Leakage,
•
Loop Back Path Delay (LB PD),
•
Duty Cycle Correction (DCC),
•
Baseband Analog Filter (BBAF),
•
Baseband Analog Filter-Group Delay (BBAF GD),
•
Attenuation Delay (ATTEN DELAY),
•
Digital to Analog Converter (DAC),
•
Path Delay.
•
Rx initial calibrations
•
High Power ADC Resistor/Capacitor (HP ADC RC),
•
High Power ADC Flash offset (HP ADC Flash),
•
High Power ADC DAC (HP ADC DAC) (currently not available),
•
Duty Cycle Correction (DCC),
•
Low Power ADC (LP ADC),
•
TIA Cutoff Frequency (TIA Cutoff),
•
Transimpedance Amplifier Group Delay,
•
Wideband Quadrature Error,
•
Frequency Independent Quadrature Error,
•
Internal Loop Back LOD (ILB LOD) (currently not available),
•
DC Offset (RF DC),
•
Gain Path Delay,
•
DMR Path Delay.
Note receiver initial calibrations are also required to be performed on loopback paths to prepare for transmitter initial and tracking
calibrations.
To successfully perform all the initial calibrations, the ADRV9001 device should be configured properly. This is fully controlled by the
ADRV9001 ARM therefore no user interaction is required. However, besides the internal configurations, there are also requirements for