Hittite Microwave Corp of Chelmsford, MA, USA (which designs and supplies analog, digital and mixed-signal RF, microwave and millimeter-wave ICs, modules and subsystems as well as instrumentation) has introduced several new, highly integrated I/Q upconverter and downconverter products which cover the licensed 38GHz and 42GHz bands in microwave radios for cellular backhaul radio links.
HMC6787ALC5A and HMC6146BLC5A are GaAs MMIC I/Q variable gain upconverters which form a competitive and cost-effective microwave radio transmitter solution which has been designed to meet or exceed all of the performance criteria required for modern high capacity QAM microwave radios. HMC6787ALC5A operates from 37 to 40GHz and provides a small signal conversion gain of 10dB with 17dBc of sideband rejection, and 13dB of gain control. HMC6146BLC5A operates from 40 to 44GHz and provides a small signal conversion gain of 12dB with 25dBc of sideband rejection, and 17dB of gain control. HMC6787ALC5A and HMC6146BLC5A both utilize a RF variable gain amplifier preceded by an I/Q mixer where the LO is driven by a x2 multiplier. IF1 and IF2 mixer inputs are provided and an external 90 degree hybrid is needed to select the required sideband. Both I/Q upconverters feature high output IP3 of +27dBm, 2LO/RF isolation of 15dB, and also meet the requirements of VSAT/Satcom transmitter terminals covering the EHF frequency band.
HMC6147ALC5A is a GaAs MMIC I/Q downconverter which is ideal for replacing the front end receiver section of 38GHz and 42GHz microwave radio designs. It provides a small signal conversion gain of 13dB with 25dBc of image rejection and utilizes a low noise amplifier to drive the I/Q mixer where the LO is driven by a x2 multiplier. IF1 and IF2 mixer inputs are provided and an external 90 degree hybrid is needed to select the required sideband. The HMC6147ALC5A I/Q downconverter also features a low noise figure of less than 3.5dB and typical input IP3 of 2dBm.
The I/Q mixer design topology used for the HMC6787ALC5A, HMC6146BLC5A and the HMC6147ALC5A reduces the need for filtering of the unwanted sidebands. All three devices provide a much smaller alternative to hybrid-style single sideband converter assemblies, and they eliminate the need for wire bonding by allowing the use of surface mount manufacturing techniques, says the firm. The HMC6787ALC5A, HMC6146BLC5A and the HMC6147ALC5A are housed in 5mm x 5mm RoHS compliant SMT packages.
Samples and evaluation PC boards for all SMT packaged products are available from stock.
