| 摘要 |
<p>This invention relates to a transceiver or transponder particularly for synthetic aperture radar, or SAR, systems, operating in a frequency band having a central frequency, said transponder comprising a receiver (1) and a transmitter (2) both thermally stable and realised by microstrip technology, said receiver (1) and said transmitter (2) being adapted to receive and to transmit, respectively, an electromagnetic wave provided with at least one linear polarisation, said receiver (1) being connected to said transmitter (2) by amplifier means comprising an amplifier unit (5) for each linear polarisation of the wave received by said receiver (1), each amplifier unit (5) including at least two amplifier stages (7, 9, 11) cascade arranged along a single microstrip and interconnected to one another and to an input and to an output of the corresponding amplifier unit (5) by means of coupling or matching stages (6, 8, 10, 12), the output signal of each amplifier unit (5) having substantially the same frequency as the input signal thereto, said amplifier units (5) having substantially the same gain, said gain being no lower than 25 dB, said transponder being phase stable so that each linear polarisation of the transmitted electromagnetic wave has phase variations in time no higher than 20°, said transponder further comprising electromagnetic decoupling means (4, 14) between said transmitter (2) and said receiver (1).</p> |
