A radio frequency signal may typically consist of a single frequency carrier signal, modulated with some information signal. The purpose of a receiver is to extract the information signal from the carrier. This is commonly accomplished by mixing the received signal with one or more local reference…

Ultra-wide-band (UWB) technology combined with multiple transmit and receive antennas can provide high data rates for indoor communications. However, designing multi-antenna systems with UWB performance is challenging because a sizable level of isolation between antennas is required to achieve eff…

The original tapered chamber was developed to reduce stray signals normally associated with a more traditional rectangular chamber. In a tapered chamber, a feed antenna is placed at the throat of a tapered section. This chamber design had several problems: the original concept could not satisfy bo…

Wireless systems are linked together through an electromagnetic field that propagates from the transmitter to the receiver, and as a result engineers must be concerned with the transmitting and receiving antennas and the propogation path to improve service. Modern wireless systems have been develo…

It is often necessary to measure physical properties, such as temperature, strain, pressure, etc, using wireless communication between sensors and the master system. Practical constraints on sensor placement, weight, size, temperature, and lifetime requirements have led engineers to design small, …

Analog-to-digital conversion is carried out in a variety of computer and communications applications. Different types of analog-to-digital converters (ADCs) have been developed to convert an analog signal, such as voltage, to a digital signal with a value that corresponds to the magnitude of the a…

Transparent metallic coatings can be used as infrared radiation reflectors and as heating elements on automobiles. These coatings have the capacity to reduce the build-up of heat inside a vehicle's cab and to reduce the need for air conditioning. Additionally, a metallic coating can be used to…

Development of reconfigurable antennas is desired by the aerospace, automotive, and communications industries. Current designs utilize a set of radiating elements connected to a transmission line with embedded amplitude and phase shift elements. An alternative technique is to use antenna modules w…

Previously, it was necessary to have three separate parabolic dish antennas, each with positioning equipment, to receive signals from three different satellites. In order to make these multiple independent contacts, communications arrays grow quickly in size with increased costs for each addition.…

Tightly Coupled Dipole Arrays (TCDAs) are popular due to their wide bandwidth, good scan performance, low profile, and low cross polarization. However, to realize their full potential, a wideband balanced feed is required. Compact wideband baluns are difficult to realize, and previous dipole array…