RF Technologies for Low Power Wireless Communications

The driving purpose of recent advances in communications technology has been to untether users, allowing them complete mobility and freedom of movement while maintaining their connection to electronic services. The wireless revolution has led to an expectation that voice, fax, and data services, and even internet access, can be available anywhere, without recourse to specific locations in a fixed infrastructure and even while moving or traveling. The last requirement tying the user to a fixed infrastructure is the requirement for power, either wall plug or battery recharging. For a commercial system, this requirement is manifested in the time between battery recharging, which is the only time the user is truly free of the fixed infrastructure. There have been very impressive advances in battery technology, resulting in longer times between battery recharges. However, battery technology is beginning to
approach practical limits, still short of the real physical limits dictated by physical chemistry. Many technologists doubt that further advances in storage battery technology will produce more than a factor of 2 improvement in battery lifetime. The other end of this issue is the electronics systems that consume the power. If
electronics systems can be designed to consume less power to accomplish the same functionality, then batteries will last longer without recharge. For military systems the situation is more complicated. Military operators of most manpacked and man portable electronic systems are accustomed to the use of disposable batteries in order to avoid the requirement for recharging during a combat operation.