tailieunhanh - Micowave and Millimeter Wave Technologies Modern UWB antennas and equipment Part 17

Tham khảo tài liệu 'micowave and millimeter wave technologies modern uwb antennas and equipment part 17', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | 472 Microwave and Millimeter Wave Technologies Modern UWB antennas and equipment RF Pulse Jitter ns 3 PRF kHz Supply Voltage min V Current consumption max @ 28 V A Weight kg 25 Dimensions 19 5U unit Table VI. Parameters of W band short pulse magnetron transmitter. In the next section some design approaches used in the above mentioned radars are described briefly. 4. Magnetron based radars - design approaches General consideration Let us to remind briefly that any magnetron based radar is featured as follows i a pulsed operational mode is used ii each RF pulse is characterized by an arbitrary phase and iii the spectrum of RF oscillation depends strongly on a shape of modulation voltage as well as on the parameters of external microwave circuits. On other hand radar operation consists conceptually in locating the received signal as respect to the radiated one in a corresponding space of signal parameters depending of the radar measurement capabilities. For example in the simplest case of non-coherent pulsed radar this space is two dimensional with coordinates of amplitude and time respectively. For Doppler radar the phase and frequency dimensions should be added. In truly coherent radar systems the exact location of radiated signal in the space of signal parameters is known a priori. Instead the above peculiarities attending the magnetron utilization in the radars require introduction of specific approaches to provide a precise location of radiated signal in such space and extend its dimensions . measurement capabilities of the radar. The most evident but comprehensive method to ensure exact location of the radiated signal is simply to measure its parameters. It is the only way to get phase information which is a key issue to implement Doppler processing. Thus each magnetron based Doppler radar should be provided with corresponding circuits to sample a small portion of radiated signal in order to measure its parameters like it is depicted in .