Analog Devices ADRV9001 User Manual

UG-1828 Preliminary Technical Data
Rev. PrC | Page 8 of 338
The LVDS electrical interface supports two modes of operation. The 32 total bits of I and Q data are serialized over one LVDS lane (32
bits composed of 16 bits of I and 16 bits of Q data) or two LVDS-SSI lanes (each dedicated to 16 bits of I or Q data), with two additional
lanes total required for a DDR clock and a frame synchronization signal. Sample rates ranging from 24 kHz to 61.44 MHz are supported
via the LVDS-SSI interface, resulting in a maximum lane rate of 983.04 MHz.
Note that in LVDS-SSI mode, 12-bit I and Q words are supported for most sample rates.
RF LO Frequency Range and Multiplexing
The ADRV9002 supports a RF LO range from 30 MHz to 6 GHz. RF LOs can be generated via two internal PLLs, or applied externally to
the device. When LOs are provided from an external source, double or more of the desired frequency must be applied to the ADRV9002
to allow for the generation of quadrature signals internally.
An LO multiplexing scheme exists on the ADRV9002, that allows for the routing of either of the RFPLLs to any of the transmit or receive
channels. The RF channels and RFPLLs can operate concurrently and independently, off a common reference clock, thus enabling: FDD
operation, single or dual frequency repeater operation, multi-band TDD operation, and diversity operation amongst various other
configurations.
Frequency Hopping
The ADRV9002 supports various forms of frequency hopping, with the main distinguishing factor between them being frequency
transition time. RFPLL phase noise, and QEC and LOL algorithm performance may degrade as a function of decreasing frequency
transition time.
A fast frequency hopping (FFH) mode exists that supports 64 hop frequencies or less, that are pre-loaded by the user onto the ADRV9002
at power-up. In this mode, the 64 frequencies are cycled through in a circular buffer fashion. Hopping between the frequencies in FFH
mode is triggered via a GPIO pin toggle. An API command with SPI transaction can also trigger a frequency hop, albeit with a longer
frequency transition time.
A random order FFH mode is also supported, whereby a finite set of frequencies already pre-loaded onto the ADRV9002 can be hopped
between in a random manner dictated by the user. Selecting the next frequency to hop to is accomplished by asserting a frequency index
word onto the GPIO bus. Alternatively, the API can be used to select the next frequency index, albeit with a longer frequency transition
time.
In addition to FFH mode, the ADRV9002 supports other frequency hopping modes where the desired hop frequencies need not be pre-
loaded into on-board memory. In these modes, desired hop frequencies can be streamed in via the API. Frequency transition times in
these modes are greater than that available in FFH mode.
Note that all frequency hopping modes are available for use in conjunction with the monitor mode described in the Power Consumption
Modes section.
Profile Switching
The ADRV9002 supports rapid switching between different RF channel profiles. A transmit or receive RF channel profile contains
settings such as bandwidth, sample rate, filtering, input port selection, AGC settings, and algorithm configuration. The profile switching
mode enables the support of waveforms that vary modulation schemes and bandwidths dynamically.
Low IF Reception
The receive digital datapath on the ADRV9002 contains an optional digital mixer that is driven by a programmable NCO. The RX LO is
offset from the frequency of the desired channel, and then the digital mixer and NCO are used to down convert signal to base-band
before being processed by their baseband processor.
There are several advantages to offset the RX LO from the frequency of the desired channel: Impairments that exist about the RX LO,
such as LO-leakage, can be avoided. The effect of flicker noise from base-band circuits can be mitigated since the received signal is offset
from DC in the analog signal path. Also, image rejection can be improved if the RX LO is offset enough from the desired channel, such
that the image frequency lies in the attenuation region of the user’s external RF filter.
The low IF reception mode is targeted predominately towards low bandwidth channels, which supports offsets range of + 20 MHz about
the receiver LO.
Receive Dynamic Range and Blocking
As depicted in Figure 2, the ADRV9002 receive path consists of an input mixer, followed by a base-band filter that drives an ADC. A
highly programmable digital decimation and filtering datapath follows the ADC. RF analog gain control is provided in analog attenuator,
and additional gain is provided in the digital datapath via AGC loops.

Analog Devices ADRV9001 Specifications

General

Brand	Analog Devices
Model	ADRV9001
Category	Transceiver
Language	English