The design and application of an intravascular extended sensitivity (IVES) MRI antenna is described. The device is a loopless antenna design that incorporates both an insulating, dielectric coating and a winding of the antenna whip into a helical shape. Because this antenna produces a broad region of high SNR and also allows for imaging near the tip of the device, it is useful for imaging long,...

1. Introduction Recently, very small antennas are requested in RFID tags and tire attached sensors of the tire pressure monitoring system (TPMS). In these applications, normal-mode helical antennas (NMHA) are interested that can achieve high antenna efficiencies at very small size such as 1/100 wavelengths. Moreover, NMHA can increase antenna gains in the metal plate proximity use. However, NMH...

In this letter, a compact circularly polarized (CP) multimode antenna for global navigation satellite system reflectometry (GNSS-R) is presented. The design comprises two quadrifilar helical antennas (QHAs), each fed with ground coplanar waveguide (GCPW) and quarter wavelength power divider (QWPD) integrated feed. A hybrid staircase-shaped (SSR) QHA radial proposed, it formed by serially...

To overcome the substantial propagation loss in ocean, a low frequency band should be chosen when contemplating radio wave communication.Then, antenna used at portable equipment very small compare to wavelength. For miniaturized antenna, normal mode helical antenna(NMHA) is suitable because of achieving high efficiency. In this paper, design method NMHA seawater condition (r=81, =4) explained...