The benefits of microwave circuits are more frequency spectrum and very short antennas. With GaAs, SiGe, and garden-variety CMOS transistors and ICs, we can inexpensively put entire microwave transceivers on a single chip. New modulation methods, like spread-spectrum and orthogonal frequency-division multiplexing, bring greater spectral efficiency and more bits/Hz of bandwidth. Plus, they’re far more robust than older modulation methods and less susceptible to noise, interference, and multipath distortion. On-chip DSPs allow us to perform signal-processing functions that previously weren’t possible.
Great new wireless developments are on the way, like e-mail and Internet access via cell phones. Wireless PDAs are now on the market. Plus, wireless LANs will become more widespread. Available for years, they haven’t been wildly popular because of their high cost and slow speed. But newer research-802.11 wireless Ethernet LANs (802.11b now and 802.11a soon) address these problems.
Home networking is with us to a small degree, but nothing will make it more acceptable and widely used than a wireless version. Stringing cable for a home LAN is a real pain. In 1995, I had a 10Base2 Ethernet LAN in my home. We had four PCs in a peer-to-peer network using Lantastic software and RG-59/U coax run under the carpet, near the wall. It would have been so much faster, easier, and neater to implement this with wireless technology.
Then we have Bluetooth, or we will soon. Many semiconductor companies are working on chips to make the “wireless-everything” promise come true. No one seems to know what the Bluetooth “killer applications” will be. But with a complete networkable 2.4-GHz radio in a $3 chip, there are bound to be some slick uses. Well, maybe not wireless everything. Do you really want to be able to set the degree of toastiness of the bread in your Bluetooth toaster from your wireless PDA?
The real benefit of Bluetooth may be personal area networks (PANs). These wireless networks cover a limited distance (less than 10 meters) and interconnect people and devices. PCs can talk to PDAs and printers, people can wear a wireless headset to communicate with a telephone, or sensors can be read by a computer. The research-802.15 standards group is defining the scope of this idea, where possibilities seem endless.
New RFID chips are revolutionizing warehousing, materials handling, and shipping operations. These short-range wireless circuits are replacing bar-code labels in many areas.
How about wireless digital satellite radios for cars, HDTVs, or the fictional wireless local loop that will give us wireless telephone connections to the central office?