RF/IF Vector Multiplier

ADL5390

Rev. 0

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FEATURES

Matched pair of multiplying VGAs

Broad frequency range 20 MHz to 2.4 GHz

Continuous magnitude control from +5 dB to −30 dB

Output third-order intercept 24 dBm

Output 1 dB compression point 11 dBm

Output noise floor −148 dBm/Hz

Adjustable modulation bandwidth up to 230 MHz

Fast output power disable

Single-supply voltage 4.75 V to 5.25 V

APPLICATIONS

PA linearization and predistortion

Amplitude and phase modulation

Variable matched attenuator and/or phase shifter

Cellular base stations

Radio links

Fixed wireless access

Broadband/CATV

RF/IF analog multiplexer

FUNCTIONAL BLOCK DIAGRAM

VPS2

OBBM

QBBP

INPI

INMI

DSOP

IBBM

IBBP

RFOP

RFOM

VPRF

CMOP

INMQ

INPQ

CMRF

Figure 1.

GENERAL DESCRIPTION

The ADL5390 vector multiplier consists of a matched pair of

broadband variable gain amplifiers whose outputs are summed.

The separate gain controls for each amplifier are linear-in-

magnitude. If the two input RF signals are in quadrature, the

vector multiplier can be configured as a vector modulator or as

a variable attenuator/phase shifter by using the gain control pins

as Cartesian variables. In this case, the output amplitude can be

controlled from a maximum of +5 dB to less than –30 dB, and

the phase can be shifted continuously over the entire 360°

range. Since the signal paths are linear, the original modulation

on the inputs is preserved. If the two signals are independent,

then the vector multiplier can function as a 2:1 multiplexer or

can provide fading from one channel to another.

The ADL5390 operates over a wide frequency range of 20 MHz

to 2400 MHz. For a maximum gain setting on one channel at

380 MHz, the ADL5390 delivers an OP1dB of 11 dBm, an OIP3

of 24 dBm, and an output noise floor of −148 dBm/Hz. The gain

and phase matching between the two VGAs is better than 0.5 dB

and 1°, respectively, over most of the operating range.

The gain control inputs are dc-coupled with a +/−500 mV dif-

ferential full-scale range centered about a 500 mV common

mode. The maximum modulation bandwidth is 230 MHz,

which can be reduced by adding external capacitors to limit the

noise bandwidth on the control lines.

Both the RF inputs and outputs can be used differentially or

single-ended and must be ac-coupled. The impedance of each

VGA RF input is 250 Ω to ground, and the differential output

impedance is nominally 50 Ω over the operating frequency

range. The DSOP pin allows the output stage to be disabled

quickly to protect subsequent stages from overdrive. The

ADL5390 operates off supply voltages from 4.75 V to 5.25 V

while consuming 135 mA.

The ADL5390 is fabricated on Analog Devices’ proprietary,

high performance 25 GHz SOI complementary bipolar IC

process. It is available in a 24-lead, Pb-free CSP package and

operates over a −40°C to +85°C temperature range. Evaluation

boards are available.