An antenna system, comprising: a first antenna apparatus, which is an active antenna system, and at least one second antenna apparatus, wherein: the first antenna apparatus comprises: a first antenna element array, a first combiner-splitter, and an active module; the first antenna element array comprises a plurality of b antenna elements, wherein b is an integer greater than 1 and the antenna elements are configured to receive and transmit signals in two different polarization directions; the first combiner-splitter is configured to combine, in the two different polarization directions, signals wherein the signals are received by the plurality of antenna elements in the first antenna element array; characterized in that the active module is configured to receive signals combined by the first combiner-splitter in the two different polarization directions, and to perform frequency translation on the signals combined by the first combiner-splitter to obtain baseband signals; and the active module is further configured to perform frequency translation on the signals, in the two different polarization directions, received via at least one pair of receiving channels from the second antenna apparatus, to obtain baseband signals, wherein the at least one pair of receiving channels is connected to the second antenna apparatus and each pair of the pairs of receiving channels is configured to receive two signals of the signals from the second antenna apparatus, one of which is in one of the two different polarization directions and the other one of which is in the other one of the two different polarization directions, wherein the second antenna apparatus comprises a second antenna element array comprising a plurality of n antenna elements, wherein n is an integer greater than 1, and a second combiner-splitter wherein the second antenna apparatus is configured to be connected, as a passive antenna, to the active module of the first antenna apparatus. the first antenna apparatus comprises: a first antenna element array, a first combiner-splitter, and an active module; the first antenna element array comprises a plurality of b antenna elements, wherein b is an integer greater than 1 and the antenna elements are configured to receive and transmit signals in two different polarization directions; the first combiner-splitter is configured to combine, in the two different polarization directions, signals wherein the signals are received by the plurality of antenna elements in the first antenna element array; characterized in that the active module is configured to receive signals combined by the first combiner-splitter in the two different polarization directions, and to perform frequency translation on the signals combined by the first combiner-splitter to obtain baseband signals; and the active module is further configured to perform frequency translation on the signals, in the two different polarization directions, received via at least one pair of receiving channels from the second antenna apparatus, to obtain baseband signals, wherein the at least one pair of receiving channels is connected to the second antenna apparatus and each pair of the pairs of receiving channels is configured to receive two signals of the signals from the second antenna apparatus, one of which is in one of the two different polarization directions and the other one of which is in the other one of the two different polarization directions, wherein the second antenna apparatus comprises a second antenna element array comprising a plurality of n antenna elements, wherein n is an integer greater than 1, and a second combiner-splitter wherein the second antenna apparatus is configured to be connected, as a passive antenna, to the active module of the first antenna apparatus.