Electronics and Telecommunications Research Institute

Nak-Seon Seong

Cheol-Sig Pyo

Jong-Suk Chae

Won-Kyu Choi

Choon-Sik Lim

Chang-Joo Kim

Ji-Hoon Bae

Jong-Moon Lee

Provided is an apparatus and method for computing the location of a radio beacon by using received signal strength (RSS) and multiple frequencies. The apparatus and method of the present invention computes the location of a radio beacon without limitation in distance by using multiple frequencies and received signal strength to resolve the problem of phase ambiguity. A radio beacon location computing system includes a plurality of base stations configured to receive signals of multiple frequencies transmitted from the radio beacon, and detect and output phase differences and received signal strength; and a location computing server configured to receive the phase differences and the received signal strength outputted from the respective base stations, acquire calculation distances based on the phase differences, remove phase ambiguity from the calculation distances based on the received signal strength, and compute the location of the radio beacon.

Apparatus and method for computing location of a moving beacon using received signal strength and multi-frequencies

Provided is an apparatus and method for computing the location of a radio beacon by using Time Difference Of Arrival (TDOA) and multiple frequencies. The apparatus and method of the present invention compute the location of a radio beacon without limitation in distance by using multiple frequencies and time difference of arrival to resolve the problem of phase ambiguity. A radio beacon location computing system includes a plurality of base stations configured to receive signals of multiple frequencies transmitted from the radio beacon, and detect and output phase differences and arrival time; and a location computing server configured to receive the phase differences and the arrival time outputted from the respective base stations, acquire calculation distances based on the phase differences, remove phase ambiguity from the calculation distances based on the arrival time, and compute the location of the radio beacon.

Apparatus and method for computing location of a moving beacon using time difference of arrival and multi-frequencies

A cable to waveguide transition apparatus having a signal accumulation form of a backshort is disclosed. The cable to waveguide transition apparatus having a signal accumulation form of a backshort, includes: a waveguide; a RF probe for transferring a radio frequency (RF) signal to the waveguide; and a backshort having the signal accumulation form for reflecting the RF signal excited from the RF probe, wherein the backshort reflects a first fundamental frequency signal excited from the RF probe to have a phase identical to a phase of a second fundamental frequency signal excited from the RF probe to an aperture of the waveguide, and reflects a first 2-order harmonic frequency signal excited from the RF probe to have a phase reverse to a phase of a second 2-order harmonic frequency signal excited to an aperture of the waveguide in order to eliminate the 2-order harmonic frequency signal.

Cable to waveguide transition apparatus having signal accumulation form of backshort and active phase shifting using the same

Provided is a dual polarization antenna realized by using four inverted F-type radiators and a Radio Frequency Identification (RFID) reader employing the dual polarization antenna. The dual polarization antenna includes a ground plate and four inverted F-type radiators set up on the ground plate. Currents of the same phase are fed to the first and second inverted F-type radiators each other. Currents of an inverted phase are fed to the third and fourth inverted F-type radiators each other. The four inverted F-type radiators form an angle of 90&#xb0; with one another. The first and second inverted F-type radiators radiate electric wave of vertical polarization and the third and fourth inverted F-type radiators radiate electric wave of horizontal polarization. Since the dual polarization antenna has excellent orthogonal and isolation characteristics, the antenna can extend a transmission distance between the reader and the tag and improve a communication quality.

Dual polarization antenna and RFID reader employing the same

Provided are a Planar Inverted-F Antenna (PIFA), a Radio Frequency Identification (RFID) tag using the PIFA. The present invention miniaturizes the antenna by using a meander line extended from a radiating edge of a radiation antenna and adjusting a resonant frequency of the antenna, and it performs impedance matching by adjusting capacitive reactance of the antenna. Also, it can perform impedance matching by using a stub having a slot formed therein and adjusting inductive reactance and capacitive reactance of the antenna. The present invention miniaturizes the antenna by using a plurality of shorting plates for shorting the radiation patch from a grounding surface and adjusting the resonant frequency of the antenna. The present invention also provides an inexpensive PIFA antenna with an excellent radiation efficiency by forming the radiation patch in the form of metal sheet in the antenna and floating the radiation patch in the air.

Growing community of inventors

Daejon, South Korea

Nak-Seon Seong