1852 results about "Dual frequency" patented technology

A dual-band antenna is provided that combines two normally disparate communications modes into a single compact aperture minimizing overall mass and volume, while maintaining high performance efficiency and reciprocity of each individual mode. The antenna is compatible with both optical (near-IR / visible) and RF (microwave / millimeter-wave) transceiver subsystems for high bandwidth communications, applicable primarily to long- to extremely long-range (space-to-ground) link distances. The optical link provides high bandwidth while the RF provides a lower data-rate weather backup, accommodation for traditional navigation techniques, and assistance in cueing the extremely tight optical beam by matching the RF beamwidth to an optical fine-steering mechanism field-of-regard. The configuration is built around a near-diffraction-limited high performance primary mirror shared by both a direct-fed RF antenna design and a Cassegrain optical telescope. Material properties are exploited to combine the optical secondary mirror with the RF feed structure, providing a collimated optical beam interface at the antenna vertex.

A dual-band feed horn having a connection surface configured for connection to a waveguide and a first surface coupled to the connection surface. The first surface has a cylindrical surface with a length and a first diameter chosen to propagate TE11 modes for both a low frequency band and a high frequency band. The horn has a bandwidth ratio of the high-frequency band to the low frequency band in the range of 1.6-4.0. The horn also has a substantially conical surface coupled to the first surface at a first slope discontinuity. The conical surface includes multiple surfaces each having a respective slope and coupled to adjacent surfaces by a respective plurality of slope discontinuities each having a respective diameter. The slopes and diameters are chosen to generate primarily TM1,m modes (m=1, 2, 3, etc.) in the high-frequency band and primarily higher order TE1,n modes (n=2, 3, etc.) in the low-frequency band such that the low frequency band and the high frequency band have approximately equal beam widths.

Ultrasound probes that transmits / receives ultrasound pulses with frequencies both in a low frequency (LF) and a high frequency (HF) band, where the radiation surfaces of said HF and LF bands at least have a common region. Several solutions for transmission (and reception) of LF and HF pulses through the same radiation surface are given. The arrays and elements can be of a general type, for example linear phased or switched arrays, or annular arrays or elements with division in both azimuth and elevation direction, like a 1.5D, a 1.75D and a full 2D array. The LF and HF element division and array apertures can also be different.