A test device 1 that measures the transmission properties or reception properties of the test object 100 having the test antenna 110, and includes an anechoic box 50, a plurality of test antennas 6 that transmit or receive radio signals to or from the antenna, under tests, a posture changeable mechanism 56 that changes the posture of the test object arranged in the quiet zone QZ, a measurement device 2 that measures the transmission properties or reception properties of the test object with respect to the test object whose posture is changed by the posture changeable mechanism using the test antenna, and the reflector 7 that radio signal is reflected. The plurality of test antennas include a reflection type test antenna 6a and the plurality of direct-type test antennas 6b, 6c, 6d.

A method of estimating a channel of a base station in a communication system using an IRS may comprise: receiving a first signal through a direct path between a terminal and the base station from the terminal and a second signal through an indirect path through the IRS from the terminal; estimating a first angle of arrival of the second signal received from the IRS; estimating a second angle of arrival of a signal transmitted to the IRS by the terminal based on the estimated first angle of arrival; estimating a third angle of arrival of the first signal received from the terminal based on the estimated first angle of arrival; and estimating path gains on the direct path and the indirect path based on the estimated first angle of arrival to the estimated third angle of arrival.

A method of estimating a channel of a base station in a communication system using an IRS may comprise: receiving a first signal through a direct path between a terminal and the base station from the terminal and a second signal through an indirect path through the IRS from the terminal; estimating a first angle of arrival of the second signal received from the IRS; estimating a second angle of arrival of a signal transmitted to the IRS by the terminal based on the estimated first angle of arrival; estimating a third angle of arrival of the first signal received from the terminal based on the estimated first angle of arrival; and estimating path gains on the direct path and the indirect path based on the estimated first angle of arrival to the estimated third angle of arrival.

An apparatus includes a fully integrated self-contained radio device including an antenna and an antenna element. The radio device and the antenna element are arranged such that a radio signal emitted by the antenna of the radio device is amplified in at least one predefined spatial direction.

A multiple co-frequency microwaves detection antenna includes an oscillation circuit unit, a reference ground and at least two radiation sources. The radiation sources each has a feed point and are arranged spacedly at the reference ground. A radiation gap is formed between each of the radiation sources and the reference ground. The feed point of the radiation source is electrically connected to the oscillating circuit unit.

In a transmitting-side control apparatus (30), a transmission control unit (32) controls a radiator (11) to transmit an OAM known signal formed by one common OAM transmission mode at each of transmitting-side relative position candidates. An acquisition unit (33) acquires a feedback signal including information about a use transmitting-side relative position based on a reception strength of the OAM known signal transmitted under the control of the transmission control unit (32). An adjustment unit (34) adjusts a relative position between the radiator (11) and a focal point of a reflecting mirror (12) to the use transmitting-side relative position indicated by the information included in the feedback signal.

In a transmitting-side control apparatus (30), a transmission control unit (32) controls a radiator (11) to transmit an OAM known signal formed by one common OAM transmission mode at each of transmitting-side relative position candidates. An acquisition unit (33) acquires a feedback signal including information about a use transmitting-side relative position based on a reception strength of the OAM known signal transmitted under the control of the transmission control unit (32). An adjustment unit (34) adjusts a relative position between the radiator (11) and a focal point of a reflecting mirror (12) to the use transmitting-side relative position indicated by the information included in the feedback signal.

A measurement system for testing a device under test is described, with at least two antennas, at least two reflectors, a signal generation and/or analysis equipment and a test location. Each of the antennas is assigned to a corresponding reflector. Each of the antennas is configured to transmit/receive an electromagnetic signal so that a beam path is provided between the respective antenna and the test location. The electromagnetic signal is reflected by the respective reflector so that the electromagnetic signal corresponds to a planar wave. The beam paths have different angular orientations that are adjustable. At least one antenna and the corresponding reflector are coupled with each other so that an integrated beam path adjustment unit is established including at least one antenna and the corresponding reflector. Further, a testing method is described.

A measurement system for testing a device under test is described, with at least two antennas, at least two reflectors, a signal generation and/or analysis equipment and a test location. Each of the antennas is assigned to a corresponding reflector. Each of the antennas is configured to transmit/receive an electromagnetic signal so that a beam path is provided between the respective antenna and the test location. The electromagnetic signal is reflected by the respective reflector so that the electromagnetic signal corresponds to a planar wave. The beam paths have different angular orientations that are adjustable. At least one antenna and the corresponding reflector are coupled with each other so that an integrated beam path adjustment unit is established including at least one antenna and the corresponding reflector. Further, a testing method is described.

The described features generally relate to adjusting a native antenna pattern of a satellite to adapt communications via the satellite. For example, a communications satellite may include an antenna having a feed array assembly, a reflector, and a linear actuator coupled between the feed array assembly and the reflector. The feed array assembly may have a plurality of feeds for communicating signals associated with a communications service, and the reflector may be configured to reflect the signals transmitted between the feed array assembly and one or more target devices. The linear actuator may have an adjustable length, or otherwise provide an adjustable position between the feed array assembly and the reflector. By adjusting the position of the feed array assembly relative to the reflector, the communications satellite may provide a communications service according to a plurality of native antenna patterns.