Abstract: A pressure guidewire is provided that has a proximal end and a distal end. The pressure guidewire has a proximal section a sensor housing section, and an intermediate section. The proximal section extends from the proximal end of the pressure guidewire to a distal end of the proximal section. The sensor housing section is disposed adjacent to the distal end of the pressure guidewire. The intermediate section disposed between the proximal section and the sensor housing section. The intermediate section has a proximal end separate from the proximal section. The proximal end can be coupled to the distal end of the proximal section. The pressure guidewire has a tubular body positioned within the intermediate section.

Abstract: There is described an optical pressure sensor comprising a sensor housing and an optical pressure cell mounted within the sensor housing and dividing the sensor housing into a first fluid space and a second fluid space. The optical pressure cell comprises a front side exposed to a pressure in the first fluid space and a back side exposed to a pressure in the second fluid space. The optical pressure sensor further comprises a fluid communication arrangement allowing pressure equalization between the pressure in the first fluid space on the front side and the pressure in the second fluid space on the back side of the optical pressure cell.

Abstract: There is described an optical pressure sensor comprising a sensor housing and an optical pressure cell mounted within the sensor housing and dividing the sensor housing into a first fluid space and a second fluid space. The optical pressure cell comprises a front side exposed to a pressure in the first fluid space and a back side exposed to a pressure in the second fluid space. The optical pressure sensor further comprises a fluid communication arrangement allowing pressure equalization between the pressure in the first fluid space on the front side and the pressure in the second fluid space on the back side of the optical pressure cell.

Abstract: A tunable resonant system includes an electric element, and a core having a controllable parameter that determines the resonant frequency of the system. In order to tune the resonant system to a desired frequency, a low power, narrowband signal is applied at a selected frequency to the electric element. The reflected or transmitted power is measured and the value of the controllable parameter adjusted to vary the resonant frequency of the system in a closed loop until the reflected power is at a minimum.

Abstract: A tunable resonant system includes an electric element, and a core having a controllable parameter that determines the resonant frequency of the system. In order to tune the resonant system to a desired frequency, a low power, narrowband signal is applied at a selected frequency to the electric element. The reflected or transmitted power is measured and the value of the controllable parameter adjusted to vary the resonant frequency of the system in a closed loop until the reflected power is at a minimum.

Abstract: An integrated dual-mode antenna including a quadrifilar antenna and a collocated monopole antenna. The integrated antenna is compact and unencumbered by signal blockage or isolation problems.

Abstract: An antenna array is disclosed wherein radiators are parasitically coupled to each other, forming an efficient feed network. Parasitic coupling of patches is arranged so that some patches are fed by a plurality of other patches which are parasitically coupled thereto. The resulting array is low profile and high gain. By positioning patches on different layers with different dimensions, a broadband design for the antenna array is achieved.