Wireless may be convenient, but it isn’t fast enough for some network links. Fiber easily does the job, yet stringing or burying fiber is a major cost and time hassle. One answer, Endwave’s E-band millimeter-wave transmit- receive (TX/RX) module pair, operates from 71.0 to 86.0 GHz for broadband point-topoint radios carrying voice and data traffic at multi-gigabit per second rates (see the figure).
The TX module typically offers a conversion gain of 15 dB and an output power of 16 dBm, with an integrated power detector on the TX output. (Higher-power transmitter options are also available.) The RX module provides a noise figure of 9 dB, better than 25 dB of RF-to-IF conversion gain, and an input one dB compression point (P1dB) of –25 dBm. Separate models cover the 71- to 76-GHz and 81- to 86-GHz operating bands.
The TX and RX modules both use Endwave’s MLMS sub-harmonic mixer topology, which provides a single level of conversion direct from the E-band to IF. This mixer design supplies functionality and performance that isn’t available in any monolithic microwave IC (MMIC) today. This architecture also significantly reduces the cost of the local oscillator (LO) circuit chain relative to the costs of comparable fundamental mixer approaches.
Additionally, the modules support modulation formats ranging from on/off keying to 16QAM (quadrature amplitude modulation). They also feature a sub-harmonically pumped TX/RX architecture and an on-board microcontroller for software-controlled compensation. Options include closedloop automatic gain control (AGC) on TX output (up to 10-dB range) and customized VCO-based (voltage-controlled oscillator) synthesizers to drive the upconversion and downconversion processes in the TX and RX, respectively.
E-band radio links provide an alternative to terrestrial fiberoptic cable that you may not know you had for your specific commercial, military, or government application. Potential uses include high-speed networks for business and campus environments; virtual private networks (VPNs); systems for carrier loop diversity and disaster recovery from central office to large office buildings; routing by cable operators (MSOs) of commercial Ethernet to extend coverage out to large building complexes; highdata- rate backhaul for cellular, WiMAX, and wireless Internet service provider (WISP) operators; HDTV signal routing; and other fiber substitution applications.
Compared to wired fiber-optic solutions, wireless E-band links offer substantially lower deployment costs, deployment speeds that are measured in days (rather than months, or even a year for fiber), and reduced regulatory and environmental approval burdens. Endwave has several prototypes working effectively in the field, and the first volume production runs have begun.
LOUIS E. FRENZEL