Orthogonal modulator from 140 MHZ to 1000 MHZ

The AD8345 is a silicon RFIC orthogonal modulator designed for use from 140 MHz to 1000 MHz. 16 pin TSSOP_EP package. Its performance is specified in the temperature range −40°C to +85°C. Its superior phase accuracy and amplitude balance enable high performance direct modulation of intermediate frequency carriers.

The AD8345 accurately splits the external LO signal into two orthogonal components through a network of polyphase splitters. The I and Q LO components are mixed with baseband I and Q differential input signals. Finally, the outputs of the two mixers are combined in the output phase to provide a single-ended 50 Ω driver at VOUT. It can be used as an intermediate frequency transmission modulator in digital communication systems such as GSM and PCS transceiver. The device is manufactured using Analog Devices' advanced silicon bipolar process.

It can also directly modulate LO signals to generate QPSK and various QAM formats for 900 MHz communication systems as well as digital television and CATV systems. In addition, the orthogonal modulator can be used with a direct digital synthesizer in a hybrid phase-locked loop to produce signals in a wide frequency range with millihertz resolution.

Features

● The operating frequency ranges from 140mhz to 1000mhz
● +2.5 dBm P1dB@800 MHz
● −155 dBm/Hz Noise lower limit
● 0.5 degree root mean square phase error (IS95)
● 0.2 dB amplitude balance
● Single power supply of 2.7 V to 5.5 V
● Pin compatible with AD8346 and AD8349
● 16 TSSOP_EP packets

Applications

● Cellular communication systems
● W-CDMA/CDMA/GSM/PCS/ISM transceivers
● Fixed broadband access systems LMDS/MMDS
● Wireless LAN
● Wireless local loop
● Digital TV/CATV modulators
● Single sideband upconverter