Improvements in relation to an apparatus for measuring the performance of a device under test, such as an antenna, a mobile phone and other wireless terminals, are disclosed. The chamber defines an internal cavity therein, adapted to enclose the device under test, and including walls of an inwardly reflective material, rendering the walls reflective to electromagnetic waves, thereby simulating a multi-path environment. Thus, the chamber is a reverberation chamber. At least one moveable object and chamber antenna are arranged in the cavity. A measuring instrument is connected to the device under test and the chamber antenna, for measuring the transmission between them. Further, an improved antenna holder is disclosed, comprising three surfaces of a reflective material, said surfaces extending in planes which are orthogonal in relation to each other and each surface facing away from the other surfaces, and wherein a chamber antenna is arranged on each of said at least three surfaces. Other improvements relate to video surveillance, channel emulation and shielding.

Method and an apparatus for measuring the performance of antennas, mobile phones and other wireless terminals

A system and method for collecting fingerprint reference wave forms under controlled conditions includes a radio frequency (RF) enclosure designed to receive a cellular telephone. A control system, including a transmitter and receiver provides RF communications with a cellular phone placed in the enclosure. A processor controls operation of the transmitter and receiver. The processor sends commands to the cellular phone in the enclosure using the transmitter. The transmitted commands are selected to elicit a RF transmission from the cellular phone in response to the command. The receiver detects the response from the cellular telephone and generates a reference wave form indicative of the transmission characteristics of the transmitter of the cellular phone in the enclosure. The processor captures one or more reference waveforms that can be used to generate a fingerprint indicative of a transmission characteristic of the transmitter of the cellular telephone. In addition, the system can include an external power supply and temperature control system to vary the voltage level of power supplied to the cellular telephone in the enclosure and to vary the temperature in the enclosure. By varying the operating voltage and temperature, the processor can collect reference waveforms under a variety of operating conditions. In addition, the processor can select the carrier frequency for the cellular telephone and for the transmitter and receiver of the control system. Furthermore, the processor can vary the transmit power of the system transmitter and the transmit power of the transmitter within the cellular telephone itself. The system is sized to be readily moved from one location to another to permit the simple collection of reference waveforms under a variety of controlled conditions.

System and method for collection of transmission characteristics

An antenna radiation pattern measurement device that measures a radiation pattern of an AUT by using a source antenna includes a control unit, an analysis unit, and a measurement unit. The control unit controls driving of the source antenna and the AUT. The analysis unit measures an electric field value from a radio frequency (RF) signal that is transmitted from one of the source antenna and the AUT and received by the other antenna. In addition, the measurement unit controls the control unit and the analysis unit and measures a radiation pattern of the AUT by using the electric field value.

Apparatus and method for measuring antenna radiation patterns

An apparatus to enable any person without measuring skills to measure an electromagnetic radiation of over 1 GHz very accurately and in a short period of time is provided, in which: rotary drive means drives and turns electronic equipment per predetermined angle, and whenever such rotation stops after covering the preceding angle, means of detecting radiation is shifted vertically by perpendicular drive means to the extent of a predetermined height; during the upward shift, detection signals continuously check and calculate the frequency spectrum that recorded the maximum field intensity of each frequency by the operation of field intensity measuring means per rotational stop, and this frequency spectrum makes it possible for data analysis means to analyze the maximum field intensity of each frequency with respect to all measured data and the directional characteristic of the field intensity at each frequency mentioned above and to output the results accordingly.

Apparatus and method for measuring electromagnetic radiation

Provided is an apparatus for measuring a read range between a tag and a reader, which includes an electromagnetic anechoic chamber formed by connecting at least one unit cell in a row, the unit cell having an electromagnetic wave absorbent provided on an inner wall of each unit cell, an electromagnetic generation portion located at the unit cell at an end of the electromagnetic anechoic chamber and transmitting an electromagnetic wave through an antenna, and an electromagnetic measurement portion which measures a field strength of the electromagnetic wave transmitted from the electromagnetic generation portion using an electric field probe moving in the electromagnetic anechoic chamber.

Apparatus for measuring read range between RFID tag and reader

A radiation field characteristic measuring apparatus comprises a rotating device for rotating a tested object through the total solid angle thereof, and a device for receiving electromagnetic waves radiated from the object, thereby measuring electromagnetic field characteristics of the object with respect to the total solid angle. According to the present invention, almost all the components of the rotating device are formed of a nonmetallic material, and spaces to allow the passage of the electromagnetic waves are formed in the components of the rotating device. Thus, reflection and scattering of the electromagnetic waves are suppressed, so that the radiation field characteristics of the tested object, with respect to the total solid angle thereof, can be obtained with high accuracy. Also, the effective radiated power is measured with use of the arrival probability density function of radio waves as a weighting function. By doing this, the evaluation index of an antenna best suited for the actual radio conditions can be obtained.

Maeda Tadahiko

Papers

Radiation field characteristic measuring apparatus