Microstrip is a planar transmission line made of a dielectric layer, similar to a coplanar waveguide. It was developed in the 1960s by ITT Federal Telecommunications Laboratories in Nutley, New Jersey, as a rival to stripline.
We can do early work with this type of transmission line using fat substrates, which allows non-TEM waves to propagate, making the results unpredictable. However, the device became very popular after the development of thinner microstrips.
A microstrip patch antenna radiates electromagnetic waves because of its fringing fields surrounding its surface. As a result, it has a low current value at the feed end and a large one at the center of the half-wave patch. This low current value accounts for the high impedance at the feed end.
To understand why this type of transmission line is called a microstrip, it is essential to understand the antenna theory. Microstrips are thin and flexible, unlike traditional transmission lines, meaning we can cut them into virtually any shape or size. This makes them the perfect solution for various applications, including RF circuits.
A microstrip line is not immersed in one dielectric material but is dielectric on both sides, which increases the characteristic impedance as the frequency increases. This property allows microstrip lines to work at very low frequencies and higher frequencies. However, this technique is limited to a few GHz due to losses.
The Most Common Printed patch Antenna
Microstrip antennas are commonly helpful in wireless communication systems. A microstrip antenna is a rectangular array with a length L that is one-third to one-half wavelength long.
They have a relatively low dielectric constant (typically 2.0 to 10.0), which results in greater efficiency. One crucial factor to consider when designing a microstrip antenna is the height of the substrate, as this directly affects efficiency and bandwidth.
A microstrip antenna consists of a metal patch connected to a dielectric substrate on one side. The patch is excited by an electrical current flowing across the dielectric substrate’s bottom ground plane.
The resulting antenna produces maximum radiation along the broadside and nearly zero radiation along the edge. The design process for a microstrip antenna often requires numerical methods to model its structure. The work of Pozar and Schawbert led to the development of sophisticated designs.
Microstrip antennas can be classified into several types but are the most popular. They play an important role in wireless communications systems due to their lightweight and thin profile. Another benefit of patch antennas is that they are easy to manufacture and are compatible with integrated circuitry.
Patch antennas are widely helpful in wireless communication systems. This is because they are easy to design and manufacture. They are also extremely inexpensive and a popular choice for various wireless applications. A rectangular microstrip antenna consists of a dielectric substrate with a metal patch on one side.
Microstrip patch Antenna benefits
A microstrip antenna is a versatile, low-cost antenna that can be manufactured easily and produces high-quality signals. Its benefits include low manufacturing cost, lightweight, and directivity. Read on to learn more about this popular antenna. You may be surprised by how many uses it has!
Low cost
Patch antennas are highly versatile and low-cost to manufacture. They are low in weight, small in size, and offer low radiation power. They can operate in dual and triple frequencies and are suited for various applications.
The low-profile design of these antennas makes them easy to incorporate into a circuit board. They are also easy to mount on a rigid surface.
Microstrip antennas are typically very thin. Therefore, we often print them on a single dielectric substrate or separately. Microstrips are a low-cost antenna design because they have no moving parts. Patch antennas consist of a layer of dielectric material. Each layer consists of 60 RF MEMS varactor elements.
Easy to manufacture
Microstrip antennas are a simple and inexpensive design that is very flexible. The planar structure allows them to conform to surfaces without losing their mechanical strength, even when mounted on rigid materials.
These antennas are helpful in many applications, and their low profile makes them easy to integrate into a device. They are also inexpensive to produce and can print onto a circuit board.
The microstrip antenna can consist of many different materials. A common material is an aluminum, which is incredibly easy to work with. We can cut and form the metal in a simple machine. The aluminum microstrip is easy to assemble, and the aluminum substrate makes it lightweight and durable.
Lightweight
Microstrip patch are low-profile, lightweight antennas that operate at a wide frequency range. In addition, they are easy to manufacture and integrate. These characteristics make them attractive candidates for use in wireless communication systems.
This paper explores various design issues related to microstrip antennas’ performance, such as gain enhancement, bandwidth, and reconfigurability. It also highlights a few examples of applications that benefit from this technology.
Patch antennas are available in a variety of shapes. The most common shape is a patch antenna, which uses a series of strips in an array. Some common shapes include a square, a circular ring, or an elliptical shape. Patch antennas are low-profile and lightweight, making them ideal for applications where space is limited.
Directivity
The directivity of a rectangular microstrip antenna is its ability to capture electromagnetic energy. We can manipulate them by changing the patch size and using an appropriate matching network. For example, a rectangular patch antenna with a width of 0.5 cm can have a gain of 0.7 dB.
Directivity is a function of the dielectric constant and the permittivity of the patch. An antenna with a larger dielectric constant has higher directivity than one with a smaller one.
Patch antennas radiate because they have a very advantageous voltage distribution. This makes them current radiators. By comparison, a wire antenna radiates because the currents add up in phase
Small distances
Patch antennas have two parts: a conductive strip and a dielectric substrate. This method is helpful for short distances, where we fabricate high-frequency signals without sacrificing efficiency.
However, it is not essential for use over a long distance. In addition, the antennas’ narrow bandwidth makes them unsuitable for use in large area networks.
Patch antennas are a relatively modern invention. They enable the integration of antenna and driving circuitry on a single circuit board or semiconductor chip.
This enables high dimensional accuracy, which was previously impossible with traditional fabrication methods. A microstrip antenna’s geometry consists of a thin dielectric substrate with a metal patch on one side.
Types of Microstrip Antennas
Microstrip patch consist of several types of materials. The conducting patch can be FR-4, RT-Duroid, foam, Nylon fabric, etc. They can also consist of dielectric substrates with different dielectric constants. The dielectric substrate is helpful for fabrication, and it is usually thick. Each type uses a different feeding technique to feed the patch to the substrate.
Parasitic patch
A parasitic patch antenna is a stacked microstrip antenna with a radiating part composed of nine rectangular metal patches arranged in three rows and three columns. Because of this regular concept makes the antenna’s radiation pattern uniform and can cover a wide bandwidth.
The antenna has a central patch 24 that couples to several smaller patches, or “parasitic patches,” which couple to each other at the center frequency f. The central patch 24 contains a slot 40 and two equal-sized notches, 44 a and b, each 125 mm wide.
As the spacing between the parasitic patches increased, so did the antenna’s profile. In addition, the antenna’s resonances shifted to lower frequencies. As a result, input impedance, reactance and resistance also decreased as the Hf increased.
Dielectric chip
The dielectric loading in a microstrip antenna profoundly affects the radiation pattern and impedance bandwidth. The higher the dielectric constant, the smaller the bandwidth of the antenna. In addition, increasing the substrate’s relative permittivity increases the antenna’s Q factor.
This is why the radiation pattern of a rectangular microstrip antenna is an array of slots. The highest directivity occurs when the dielectric of the substrate is air. Therefore, the relative permittivity of the dielectric increases as the substrate becomes more dielectric.
Antennas with high efficiency and high bandwidth have the advantage of being small and lightweight. However, there are several disadvantages to using a thin dielectric. Firstly, the ground plane significantly affects a microstrip antenna’s radiation resistance. Secondly, a microstrip antenna’s efficiency is negatively affected by the size of the dielectric.
A microstrip patch antenna is widely helpful in wireless communication systems. They are easy to make, and we can produce them in various shapes. The most common type is a patch antenna, but other microstrip patch use the patch as a constitutive element.
Patch
Microstrip antenna patch design can be challenging, especially if you need to increase bandwidth and cross-polarization. Fortunately, there are solutions. One of the easiest methods is to increase the height of the substrate. This will result in a larger effective radiation height. Another way to increase the effective radiation height is to use multiple patches.
Microstrip antenna patch designs consist of a probe connected to the patch and the ground plane. This method allows for efficient feeding and minimizes spurious radiations.
Another method, called aperture coupled feeding, couples the patch antenna to the feeder through a slot in the ground plane. This technique minimizes the likelihood of interference and increases the antenna’s bandwidth.
Microstrip antenna patch designs are also easy to manufacture. These thin antennas are lightweight and compact and suitable for flexible mounting on flexible circuit boards. Microstrip antenna patch designs are widely helpful in mobile communication and other areas. These antennas are also useful for remote sensing and environmental instrumentation.
Microstrip
A microstrip antenna is a type of internal antenna. They are most helpful for microwave frequencies. They consist of thin strips of metal, and are useful in many applications. These strips consist of gold or silver. This type of antenna is also commonly helpful in microwave ovens. A microstrip antenna is beneficial in many applications where a longer, stronger antenna is needed.
The radiation of antenna elemets are a function of the fringinging field surrounding the antenna. A side view shows that the current is zero at the end of the patch and is maximum at the center of the half-wave patch. This explains why the antenna impedance is so high at the end.
Microstrip patch is inexpensive and easy to manufacture. Their size is directly related to the wavelength at the resonant frequency. Single patches typically provide 6-9 dBi of directive gain, but patch arrays are capable of higher gains. In addition, the patches we can print using lithographic techniques. This type of antenna is also helpful for phase adjustment and matching.
Microstrip Antenna features
Microstrip antennas are two-dimensional physical geometries that are cheap to produce, and we can print on substrates. They are helpful in various applications, including GPS technology, mobile satellite communications, Direct Broadcast Satellite (DBS) systems, remote sensing, and more. In addition to these uses, a printed antenna are also helpful in non-satellite applications, including medical hyperthermia.
Low-profile
Low-profile microstrip transmission line is ideal for use in mobile satellite communications systems. These antennas are flexible enough to conform to land vehicle roofs or aircraft wings.
One such antenna is in U.S. Pat. No. 5,220,335 (Huang). It includes microstrip patch elements and is tilted 40 degrees from its normal direction. This antenna has a low profile and high radiation efficiency, which is necessary for efficient mobile communications.
The design must reduce the overall size of a microstrip antenna. This process involves several optimization stages. The first step is to analyze the geometry of a proposed microstrip antenna. Once the geometrical parameters are determined, the design process will begin. This process is called characterization.
This antenna is a low-profile, rectangular patch microstrip antenna that operates on two frequency bands at once. We can achieve the dual-band characteristic by adjusting the slot size and inset-feed point.
One then prints the designed antenna onto an FR4 substrate. Measurements indicate that the realized antenna works on dual bands with a bandwidth of 45 MHz and 95 MHz. It also achieved a gain of 4.08 dBi for 1.8 GHz and 5.79 dBi for 2.4 GHz.
A low-profile printed antenna is excellent for mounting on metallic objects. These antennas can be as small as 1.6 mm in thickness. They offer high gain and a low profile. They are suitable for many UHF radio frequency identification applications. One advantage of these antennas is their versatility and low cost
Low-profile microstrip antennas offer high performance and wide bandwidth. The proposed antenna has a TM10-mode co-excited, TM20-mode antiphase, and a well-matched slotline transition.
Wideband
Wideband microstrip antennas are reconfigurable antennas with adjustable bandwidth and frequency. They are widely helpful in commercial, industrial, and military applications. The current research focuses on reconfigurable antennas with wide bandwidth and flexible frequencies. The proposed antennas have numerous applications and can easily integrate into a wide range of wireless devices.
A wideband printed antenna comes in different shapes and modes. They can be circular, dipole, square, or rectangular. Each shape has different radiation properties. The dipole is convenient as it has favorable radiation characteristics and occupies less space. Single and multi-feed arrays are also available for this technology.
The dielectric constant of the substrate is closely related to the width and bandwidth of the antenna. Therefore, if the dielectric constant is low, the antenna will have higher bandwidth. On the other hand, if the dielectric constant is high, the antenna will be compact and smaller. Therefore, the dielectric constant is a critical parameter in designing a microstrip antenna.
A wideband microstrip antenna is an extension of the traditional microstrip antenna. Its frequency response is comparable to that of its matched-pattern counterparts. Input impedance bandwidth is twice that of a traditional microstrip antenna. Its resonant frequency range is 4.72 to 6.79 GHz.
Wideband microstrip antennas have a lower impedance bandwidth than monolithic antennas, but they can be helpful for wireless applications. The design of the wideband microstrip antenna is a combination of both.
Microstrip antennas can radiate frequencies ranging from 2.7 GHz to 9.5 GHz. Therefore, this antenna is widely helpful in wireless communications. Its design features a defected ground plane to improve the gain. The maximum gain of the wideband microstrip antenna is 34 dB at 3.55 GHz.
Inefficient
Microstrip antennas are often curved and triangular. These shapes provide better impedance matching. The properties of an efficient microstrip antenna depend on its size, which typically ranges from five to six dB. In addition, the antenna design depends on the resonance frequency and pattern required. Finally, we choose the slots to produce the necessary bandwidth and gain.
Inefficient antenna elements have several disadvantages. They have low efficiency, poor power, and poor polarization purity. They also have a limited frequency bandwidth. However, in some applications, they can replace horn antennas. In addition, we can make them in various shapes and sizes.
An efficient microstrip antenna is an essential component in next-generation wireless communication systems. Its use in 5G communication systems is necessary to meet the exponential growth in data traffic.
However, this technology demands antenna arrays that are low profile. Microstrip patch antennas are a viable option but still have several drawbacks, such as low directivity and substrate thickness.
We can explain the radiation characteristics of an inefficient microstrip antenna in terms of fringing fields. For example, when you look at a patch antenna in a side-on view, you can see that the current is zero at the end. This is because the current in the patch is maximum in the center of the half-wave patch. The low current value at the end of the patch explains the high impedance.
Graphene offers greater bandwidth than copper. Additionally, it has a reduced resistance. Graphene also reduces stub-matching problems. Graphene can also be helpful in ultra-wideband applications.
Design and Measurement of Microstrip Antenna
Microstrip antennas are widely helpful for mobile communication systems. They are thin-film structures characterized by a narrow bandwidth and a circular or rectangular shape.
The most common type of MSA is a rectangular structure without a ground plane or dielectric material. The rectangular structure has a single polarization with radiating edges at each end of the L-dimension. Therefore, the radiation at the W-dimension is much less, called cross-polarization.
EM waves radiate out on a ground plane
Microstrip antennas radiate electromagnetic waves by combining two or more parallel layers of material. Therefore, we can stack these strips to improve directivity and bandwidth. In addition, leaky waves can further increase the antenna’s directivity. These advantages make antenna elements a popular choice for wireless communications.
Microstrip antennas can radiate waves in many different wavelength ranges. This allows for the creation of a wide variety of wireless communications devices. These antennas can consist of metal, plastic, or even glass. Many of them also have high transmission efficiency and low insertion loss.
Microstrip antennas are generally rectangular. They are made of a high conductivity metal, usually copper. The metal patch sits on top of a dielectric substrate. The substrate thickness is not critical, but the height h must be smaller than the wavelength of operation. If the height is too small, the antenna will not radiate efficiently.
EM waves contribute to the radiation pattern
The contribution of EM waves shapes the radiation pattern of a Microstrip antenna. Several factors contribute to this radiation pattern. One of these factors is substrate thickness. An antenna with a thin dielectric substrate has a lower effective radiation height than one with a thick substrate.
A parasitic patch is an additional element that can increase the radiation height. We can optimize the antenna’s effective radiation height by adjusting the size of the parasitic patch. One often prints them on a dielectric substrate with a foam layer on top of it.
A microstrip antenna array is very simple and inexpensive. Their main advantages include their high-frequency sensitivity, low-cost, low-profile, and lightweight design. They are also highly efficient and have high gains.
EM waves contribute to the impedance bandwidth
A microstrip antenna is a rectangular patch of metal that is excited by a voltage source across its bottom ground plane. It produces optimum radiation when excited in broadside directions and virtually zero radiation along the edges. A microstrip antenna can be modeled accurately by numerical methods. Pozar and Schawbert developed sophisticated designs for the microstrip antenna.
The microstrip antenna impedance bandwidth depends on the frequency of EM waves. For example, at 868 MHz, the antenna’s resonant frequency is too high. To minimize the frequency response, a discrete matching network may be helpful, which includes a 6.5-pF parallel capacitor and a 21.8-nH serial inductor.
Using software simulations to design a microstrip antenna array is essential for ensuring optimum performance. For example, using a simulation program like Sonnet, you can design matching networks to ensure that the antenna’s impedance bandwidth is optimized and that power transfer is near perfect.
EM waves contribute to the scan blindness
To minimize scan blindness, the antenna should reduce EM waves that propagate along its edges. However, conventional bandgap materials cannot eliminate the problem. Their radiating modes propagate in the substrate and couple elements, making them incapable of functioning as isolated radiating elements. To minimize scan blindness, the antenna should have modes that can suppress surface and substrate waves.
The scan blindness angle of a metal dielectric antenna depends on the substrate thickness and the permittivity. Using TSS, we can eliminate scan blindness in the H plane. The TSS acts as a hard surface in the H plane and guides the waves between the antenna elements.
In addition, the interelement spacing is uniform. Therefore, calculating scan blindness makes it possible to predict the antenna’s performance based on the propagation constants.
EM waves from microstrip antennas generate as they pass through the antenna. The dielectric under the patch causes polarisation currents, contributing to far-field coupling. The dielectric under the patch is also responsible for mutual coupling.
