Millimeter-wave antenna array apparatus
The present invention relates to a millimeter wave RF antenna array apparatus. The apparatus comprises a single-chip MMIC comprising active circuit elements of the antenna array apparatus. The active circuit elements comprise at least antenna feed circuitry configured to feed antenna elements of the antenna array. The apparatus comprises an interposer fabricated of low-loss RF material, such as glass, low-temperature co-fired ceramic, LTCC, or printed circuit board, PCB. The interposer comprises transmission lines of a RF distribution network and a plurality of antenna elements of the antenna array. The transmission lines of the interposer are coupled to the MMIC for providing RF connections for distributing RF signals to and from the antenna feed circuitry. Area of the interposer that comprises the transmission lines of the RF distribution network and the plurality of antenna elements is collocated with the area of the MMIC that comprises said antenna feed circuitry.
1 . A millimeter wave radio frequency, RF, antenna array apparatus comprising a single-chip monolithic microwave integrated circuit, MMIC, comprising active circuit elements of the antenna array apparatus, wherein the active circuit elements comprise circuit elements of a transmitter or a receiver and antenna feed circuitry configured to feed a plurality of antenna elements of the antenna array, the antenna array apparatus comprising:
an interposer fabricated of low-loss RF material, such as glass, low-temperature co-fired ceramic, LTCC, or printed circuit board, PCB, wherein the interposer comprises transmission lines of a RF distribution network and the plurality of antenna elements of the antenna array, and
electrical contacts between the interposer and the MMIC,
wherein said transmission lines of the RF distribution network on the interposer are coupled to the MMIC for providing RF connections for distributing RF signals via active circuit elements of the MMIC to and from the antenna feed circuitry comprised in the MMIC, so that the RF signal travels via said electrical contacts back and forth between active circuit elements in the MMIC and portions of transmission lines of the RF distribution network in the interposer and in that area of the interposer that comprises said transmission lines of the RF distribution network and the plurality of antenna elements is similar to lateral dimensions and collocated with the area of the MMIC that comprises said antenna feed circuitry, so that active circuitry on the MMIC that processes a receive RF signal on a respective receive signal path or a transmit RF signal on a respective transmit signal path for a respective antenna element is collated with the respective antenna element.
2 . The antenna array apparatus according to claim 1 , wherein each portion of the MMIC comprising a portion of the antenna feed circuitry configured to feed the respective antenna element is collocated with the portion of the interposer comprising the respective antenna element.
3 . The antenna array apparatus according to claim 1 , wherein the antenna feed circuitry comprises active circuit elements for performing beamforming, such as a variable gain amplifier, and a phase shifter.
4 . The antenna array apparatus according to claim 1 , wherein the antenna array apparatus comprises a plurality of said transmit signal paths, each transmit signal path being a route traveling from an output of the transmitter via respective portions of transmission lines of the RF distribution network on the interposer and via respective antenna feed circuitry of the transmit signal path in the MMIC to an input of one of the plurality of antenna elements, and/or wherein the antenna array apparatus comprises a plurality of said receive signal paths, each receive signal path being a route traveling from an output of one of the plurality of antenna elements via the respective antenna feed circuitry of the receive signal path in the MMIC and via respective portions of the transmission lines of the RF distribution network on the interposer into an input of the receiver.
5 . The antenna array apparatus according to claim 1 , wherein the active circuit elements comprise at least one of a transmitter, a receiver, an amplifier, a phase shifter, an analog-to-digital converter, a digital-to-analog converter, and a serial peripheral interface, and wherein the MMIC further comprises DC supply voltage interconnections and/or digital distribution networks such as serial peripheral interface interconnections.
6 . The antenna array apparatus according to claim 1 , wherein the RF distribution network comprises one or more power dividers.
7 . The antenna array apparatus according to claim 6 , wherein said one or more power dividers are comprised in the MMIC and/or in the interposer.
8 . The antenna array apparatus according to claim 7 , wherein the MMIC comprises at least one first power divider on a transmit signal path or a receive signal path, and wherein the interposer comprises one or more further power dividers on the respective transmit or receive signal path, wherein the one or more further power dividers are further away from the respective antenna element, along the respective transmit signal path or receive signal path, than the at least one first power divider.
9 . The antenna array apparatus according to claim 6 , wherein power division obtained by said plurality of power dividers is symmetrical or asymmetrical, and wherein possible asymmetry of the power division network is compensated by one or more amplifiers and phase shifters of the antenna feed circuitry.
10 . The antenna array apparatus according to claim 1 , wherein the interposer and the MMIC are mutually connected using flip-chip technology that forms the plurality of electrical contacts between the MMIC and the interposer, wherein the electrical contacts are configured to maintain at least a minimum predefined vertical distance between the MMIC and the interposer for avoiding interference.
11 . The antenna array apparatus according to claim 10 , wherein the plurality of electrical contacts are solder balls, copper pillar bumps or stud bumps.
12 . The antenna array apparatus according to claim 1 , wherein the interposer and the MMIC are mutually connected using both electrical contacts and electromagnetic coupling, such as capacitive or inductive coupling, which jointly form a plurality of coupling points between the MMIC and the interposer, wherein the electrical contacts are configured to maintain at least a minimum predefined vertical distance between the MMIC and the interposer for avoiding interference.
13 . The antenna array apparatus according to claim 1 , wherein
the interposer is a single-layer or a multi-layered structure.