Discussion
What is the far field pattern of a uniformly illuminated rectangular aperture?
Answer: A
The transform of a rectangle is a sinc, so each principal plane shows the familiar narrow main lobe with side lobes 13.2 decibels below it. A circular aperture gives the Bessel form instead, which is the Airy pattern of optics with side lobes at minus 17.6 decibels. A Gaussian aperture would give a Gaussian pattern but cannot exist in finite size, and the cosine squared form belongs to a particular taper rather than to uniform illumination. Knowing the two canonical transform pairs covers most aperture problems at the estimating stage.
No comment is present. Be the first to comment.
Loading…
Post your comment
Please log in or register to post a comment.
Examination Categories
- SSC Exams
- Banking Exams
- Teaching Exams
- Civil Services Exams
- Railways Exams
- Engineering Recruitment Exams
- Defence Exams
- State Government Exams
- Police Exams
- Insurance Exams
- Nursing Exams
- Other Government Exams
- NRA CET
- PG Entrance Exams
- Campus Placement
- MBA Entrance Exams
- CUET and UG Entrance
- Judiciary Exams
- Regulatory Body Exams
- Software Development