Tutorials Point is a leading Ed Tech company striving to provide the best learning material on technical and non-technical subjects.

Parabolic Reflectors are Microwave antennas. For better understanding of these antennas, the concept of parabolic reflector has to be discussed.

Olympusmicroscope

Tutorials Point is a leading Ed Tech company striving to provide the best learning material on technical and non-technical subjects.

OlympusCX43

Usually a wave guide horn antenna is used as a feed radiator for the paraboloid reflector antenna. Along with this technique, we have another type of feed given to the paraboloid reflector antenna, called as Cassegrain feed.

The gain of the paraboloid is a function of aperture ratio (D/λ). The Effective Radiated Power (ERP) of an antenna is the multiplication of the input power fed to the antenna and its power gain.

ZEISS microscope

When the antenna acts as a transmitting antenna, the energy from the feed radiates through a horn antenna onto the hyperboloid concave reflector, which again reflects back on to the parabolic reflector. The signal gets reflected into the space from there. Hence, wastage of power is controlled and the directivity gets improved.

Munday Scientific offers a wide range of Olympus microscopes new, used and refurbished with competitive pricing.  We focus on used and refurbished Pathology and Mohs microscopes, but stock microscopes for all applications.  If not new, the microscopes are fully serviced, tested and warrantied.  By purchasing a used microscope you will have a faster lead time and a fully serviced, great working microscope at almost 50 percent of the price of a new system.

BX43olympus

The reflected wave forms a colllimated wave front, out of the parabolic shape. The ratio of focal length to aperture size (ie., f/D) known as “f over D ratio” is an important parameter of parabolic reflector. Its value varies from 0.25 to 0.50.

parabola when used for the purpose of reflection of waves, exhibits some properties of the parabola, which are helpful for building an antenna, using the waves reflected.

The law of reflection states that the angle of incidence and the angle of reflection are equal. This law when used along with a parabola, helps the beam focus. The shape of the

OlympusBX53

OlympusCX23

The figure clearly depicts the working pattern of all the types of reflectors. There are other types of paraboloid Reflectors such as −

Olympus upright microscopes provide excellent ergonomics for comfortable operation and high quality optics for high color reproducibility.  Modular options allow different observation styles like polarization, brightfield, darkfield, fluorescence and phase contrast.  The Olympus stereo microscopes offer the same quality of design with a clear stereoscopic view.  It also offers a wide zoom ratio for smooth macro-to-micro viewing.

"Great company! Chad is knowledgeable and easy to work with and they are committed to customer satisfaction. Highly recommended."

Hence, of all the types of reflector antennas, the simple parabolic reflectors and the cassegrain feed parabolic reflectors are the most commonly used ones.

When the same antenna is used for reception, the electromagnetic waves strike the reflector, gets reflected on to the concave hyperboloid and from there, it reaches to the feed. A wave guide horn antenna presents there to receive this signal and sends to the receiver circuitry for amplification.

The following figure shows the geometry of parabolic reflector. The point F is the focus (feed is given) and V is the vertex. The line joining F and V is the axis of symmetry. PQ are the reflected rays where L represents the line directrix on which the reflected points lie (to say that they are being collinear). Hence, as per the above definition, the distance between F and L lie constant with respect to the waves being focussed.

OlympusSZ61

The standard definition of a parabola is - Locus of a point, which moves in such a way that its distance from the fixed point (called focus) plus its distance from a straight line (called directrix) is constant.

Some of the power that gets reflected from the parabolic reflector is obstructed. This becomes a problem with small dimension paraboloid.

This is another type of feed used. A pair of certain configurations are there, where the feed beamwidth is progressively increased while antenna dimensions are held fixed. Such a type of feed is known as Gregorian feed. Here, the convex shaped hyperboloid of casssegrain is replaced with a concave shaped paraboloid reflector, which is of course, smaller in size

CKX53

"Very helpful, reliable, and professional personnel. I worked with Chad, he will help you in anyways possible to make sure you get what you need and you are happy with your product. Thanks!"

Casse grain is another type of feed given to the reflector antenna. In this type, the feed is located at the vertex of the paraboloid, unlike in the parabolic reflector. A convex shaped reflector, which acts as a hyperboloid is placed opposite to the feed of the antenna. It is also known as secondary hyperboloid reflector or sub-reflector. It is placed such that its one of the foci coincides with the focus of the paraboloid. Thus, the wave gets reflected twice.

The same antenna is used as a receiver. When the electromagnetic wave hits the shape of the parabola, the wave gets reflected onto the feed point. The dipole or the horn antenna, which acts as the receiver antenna at its feed, receives this signal, to convert it into electric signal and forwards it to the receiver circuitry.

If a Parabolic Reflector antenna is used for transmitting a signal, the signal from the feed, comes out of a dipole or a horn antenna, to focus the wave on to the parabola. It means that, the waves come out of the focal point and strike the Paraboloidal reflector. This wave now gets reflected as collimated wave front, as discussed previously, to get transmitted.

All the waves originating from focus, reflects back to the parabolic axis. Hence, all the waves reaching the aperture are in phase.

The frequency range used for the application of Parabolic reflector antennas is above 1MHz. These antennas are widely used for radio and wireless applications.

Olympus microscopes are over a century old and have been the top pick of microscopes for doctors, professors, researchers and students.  The Olympus BX series microscope is the industry standard for Pathologists and Mohs surgery centers across the US.  The most popular microscope we sell is the Olympus BX41.  This microscope is absolutely excellent and our top pick for clinical applications.