Over the air measurement module
An over the air measurement module comprises an antenna, adapted to receive a first measuring signal from a device under test or to transmit a second measuring signal to the device under test. It also comprises an analog signal processor, directly connected to said antenna, adapted to reduce a frequency of the received first measuring signal, resulting in a frequency reduced first measuring signal, or adapted to increase a frequency of a frequency reduced second measuring signal, resulting in the second measuring signal. It also has a connector connected to said analog signal processor and is adapted to output the first frequency reduced measuring signal or is adapted to receive the second frequency reduced measuring signal.
1. An over the air measurement module, comprising:
an antenna, adapted to receive a first measuring signal from a device under test or adapted to transmit a second measuring signal to the device under test,
an analog signal processor, directly connected to said antenna, adapted to reduce a frequency of the received first measuring signal, resulting in a frequency reduced first measuring signal, or adapted to increase a frequency of a frequency reduced second measuring signal, resulting in the second measuring signal, and
a connector, connected to said analog signal processor, adapted to output the first frequency reduced measuring signal, or adapted to receive the second frequency reduced measuring signal,
wherein the antenna is a planar antenna, and wherein a main radiation direction of the antenna is in the plane of the planar antenna,
wherein at least some surfaces, of the over the air measuring module facing in the main radiation direction of the antenna are adapted to absorb electromagnetic radiation and not reflect electromagnetic radiation, and
wherein at least 50% of surfaces of the over the air measurement module facing the main radiation direction of the antenna are angled away from a normal of the main radiation direction of the antenna by at least 30°.
2. The over the air measurement module according to claim 1 , wherein at least some surfaces of the over the air measuring module facing in the main radiation direction of the antenna are coated with a paint absorbing electromagnetic radiation or covered with absorber material absorbing electromagnetic radiation or fabricated from absorber material absorbing electromagnetic radiation.
3. The over the air measurement module according to claim 1 , wherein over the air measurement module is tapered towards the main radiation direction of the antenna.
4. The over the air measurement module according to claim 1 , wherein, if the antenna is adapted to receive the first measuring signal from the device under test, the analog signal processor is adapted to reduce the frequency of the received first measuring signal, and the connector is adapted to output the first frequency reduced measuring signal, and the analog signal processor comprises a mixer, adapted to down convert the first measuring signal to the frequency reduced first measuring signal.
5. The over the air measurement module according to claim 4 , wherein the analog signal processor further comprises: a filter, adapted to perform a filtering of the first measuring signal or of the first frequency reduced measuring signal, or a power sensor, adapted to measure the power of the first frequency reduced measuring signal, or an amplifier, adapted to amplify the first measuring signal or the first frequency reduced measuring signal, or a radio frequency switch, adapted to switch between different operating modes of the over the air measurement module.
6. The over the air measurement module according to claim 1 , wherein, if the connector is adapted to receive the second frequency reduced measuring signal, the analog signal processor is adapted to increase the frequency of the frequency reduced second measuring signal, the antenna is adapted to transmit the second measuring signal to the device under test, and the analog signal processor comprises a mixer, adapted to up convert the frequency reduced second measuring signal to the second measuring signal.
7. The over the air measurement module according to claim 6 , wherein the analog signal processor further comprises: a filter, adapted to perform a filtering of the second measuring signal or the second frequency reduced measuring signal, or an amplifier, adapted to amplify the second measuring signal or the second frequency reduced measuring signal, or a radio frequency switch, adapted to switch between different operating modes of the over the air measurement module.
8. The over the air measurement module according to claim 1 , wherein over the air measurement module comprises a substrate, advantageously a printed circuit board, wherein the antenna and the analog signal processor are arranged on the substrate, wherein the antenna is planar with the substrate, and wherein the main radiation direction of the antenna is towards an edge of the substrate.
9. The over the air measurement module according to claim 8 , wherein the substrate has a relative permittivity ε r of ε r <4, preferably ε r <2, most preferably ε r <1.5 or wherein the substrate has a relative permeability μ r of μ r <3, preferably μ r <2, most preferably μ r <1.5.
10. The over the air measurement module according to claim 8 , wherein the antenna is a tapered slotline antenna, preferably a Vivaldi antenna.
11. The over the air measurement module according to claim 10 , wherein the substrate comprises an opening between conductors of the tapered slotline antenna, or wherein a substrate bridge connects opposite parts of the tapered slotline antenna in an area of an antenna aperture.
12. Measuring system comprising an over the air measurement module according to claim 1 and a measuring device, wherein the measuring device is adapted to receive and measure the frequency reduced first measuring signal from the over the air measurement module or is adapted to provide the frequency reduced second measuring signal to the over the air measurement module.