THE BUTLER MATRIX FOR A DECIMETRIC BAND
This product is a relatively compact realization of a well-known Butler matrix. Technical characteristics achieved in this design make it possible to do frequency-independent multibeam antenna arrays with a high resolution and a low sidelobe pattern.
This Butler matrix provides acceptable characteristics for many practical applications in an extended frequency band from 650 to 1100 MHz.
A concept founded in this design and existing detail parts allow to build similar products for higher frequencies (to 5-6 GHz).
I/O numbers 32×32;
Working frequency range 820-900 MHz;
Dissipative loss < 2 dB;
Mean-square gain deviation:
Magnitude < 0.5 dB;
Angle < 4 deg;
Dimensions 440x210x90 mm.
Joint product of
OJSC “GDB “LUCH” , SPRUE “DB RADAR”, SPDUE “WOLOTAVTO”
of formation and switching of multibeam mode
Microwave module is used for work as a part of active phased arrays of multifunctional radar and information systems of enhanced interference immunity
Microwave module provides:
- formation of four receive/transmit beams in the active phased array, independently scanning their working sectors of information system.
Peculiarities of the formation of an active phased array with the use
of microwave module:
- An active phased array consists of two components: analog microwave circuit of module formation and receive/transmit system based on digital technologies.
- Analog part of an active phased array includes an array of radiating elements, grouped into a system of sub-arrays with 16 elements in each of them, receive/transmit modules (RTM) installed on the radiator inputs, microwave modules of formation and switching of multibeam module, consisting of 16-channels diagram-forming circuit, that forms a fan of 16 beams, and matrix microwave switch on pin-diodes providing connection to the working channels of an active phased array of any 4 of 16 array beams.
- Receive/transmit system based on digital technologies consists of 16 times less than in a entirely digital active phased array number of digital channels in every of 4 independent system beams and provides formation of directional characteristic of the active phased array, adaptive signal processing and functional control of the active phased array system as a whole.
- Module of formation and switching of the multibeam mode is a multi-layer structure consisting of 6 symmetric striplines in which the elements of the diagram-forming circuit, matrix switch and control electronics are situated. Boards (cards) of maximum size 300×300 mm2 are made of “Rodgers” material, “MACOM” pin-diode is used as a switching element.
- Microwave module is worked out for C-band with working frequency band of 10 %.
- Maximum speed of beam switching is 0.1 microsecond.
- Wave impedance of paths is 50 ohm.
- Power loss in the module of formation and switching of multibeam mode is not more than 6 dB.
- Modular construction makes possible the formation of full aperture of the active phased array with the number of elements multiple of the number of the radiating elements in the sub-array.
- Number of independent beams formed in the active phased array is defined by the characteristics of the matrix switch (in the variant involved it’s 4 out of possible 16). The choice of the number of independent beams and sub-arrays size can control the ratio of analog microwave equipment and digital equipment, forming transmitting and receiving modes of the system, which makes possible optimization of the product according to the criterion “price – effectiveness”.
- Receive-transmit modules function only as signal amplifiers. The formation of the amplitude-phase distribution is carried out by stages: within sub-arrays – by the module of formation and switching of the multibeam mode, within the whole sub-arrays ensemble – by the digital receive/transmit equipment.
- Practical realization of the multibeam working mode of the active phased array and optimization of receiving and transmitting modes presupposes the use of frequency (within the working band) and time channel separation.
Our enterprise is ready to develop a module of formation and switching of multibeam mode with the number of channels 16, 32, 64 in the needed frequency range and to manufacture it.