the matrix receiver (MR)
multichannel functional receiver (МFR)
frequency channel (FC)
a range of frequencies
overlapping of a range of frequencies
combinational channels of reception (CCR)
instant measuring instrument of frequency
J.P. Melnikov and S.V. Popov
In the article in accordance with a classical definition of Rayleigh’s criterion a point targets SAR resolution depended on a sounding signal bandwidth and an angle synthetic aperture is considered. A mathematical description of two-dimensional diagram of uncertainty is given and a potential resolution is averaged out. Change resolution limits are indicated. An angle value of synthetic aperture for a resolution minimum difference is concretized.
Multi-channel functional receiver (МFR), as is known, contains some consecutive steps of transformation of frequency, each of which has a number of parallel frequency channels (FС) with adjoining pass-bands. The strip of frequencies of each of FС the given step is transferred to transformation to a range of frequencies of the following step. Frequency of a signal is defined on a combination of numbers FС in consecutive steps where reception of a signal took place. Advantage МFR in comparison with a usual multi-channel measuring instrument of frequency with a set parallel FC is essential reduction of number FC and by that weights of the equipment. As lacks we shall note the raised complexity of the equipment and algorithm of definition of frequency, and also an opportunity of formation of false combinational channels of reception.
In article questions of optimization of structural construction МFR and opportunities of continuous overlapping of a wide range of frequencies are considered at use of minimal number FС in view of minimization of quantity of false receptions in a dynamic range due to combinational channels of reception (CCR) and simultaneous reception of a signal in next FС.
In article are received:
- Formulas and schedules for definition of optimum number of steps and quantities FC in view of conditional weight factors of technical elements included in them,
- Technique of a choice of borders FC and types of transformation in steps on a basis номограмм with minimization of quantity and levels CCR,
- Example of structure MFR on a range 0.1÷10 GHz with common number FC about 50 and quantity of resolved gradation about (1÷2) •103 with use for reception FC of intermediate steps,
- Logic algorithm of definition FC of reception of a signal in consecutive steps in view of types of transformation,
- Variant of step МFR with numerous use FC due to application of multiplication of frequency and re-circulation a signal.
The techniques of definition of optimum number of steps of transformation stated in article and quantities FC, ways of arrangement FC and a choice of types of transformation with account CCR, and also ways of application of multiplication of frequency can be used at designing and the comparative estimations of efficiency of various variants of construction МF working in a wide wave band.