Triple Bands VHF and UHF Antennas

VHF and UHF mobile handheld (Walkie Talkie) radios are utilized by many.

Due to operating wavelength, they have range from few to tens of kilometers depending on the environment and condition.

The mobility requires compact, low weight, low power radio.  Antenna design Triple Bands topology is highly desired.

Partner with ORTENGA for your mutliband antenna design and development.

 

 

Multi Band Antenna

BT and WiFi share 2.4 GHz ISM band.  In addition, WiFi technology has 5 and 6 GHz bands.

A router or handheld device which supports both BT and WiFi would need to support multi band between 2 to 7 GHz.  Therefore, designing antenna aperture and radio front end that support multi bands is highly desirable.

In the case of wearable devices, the form factor of the mobile device is of prime concern.

In addition, the material and proximity in close space becomes challenging for typical antenna designer.

Augment ORTENGA in your wearable multi band antenna design and development.

WiGig Antenna

WiGig Antenna subsystem would require 25% fractional bandwidth.  The antenna subsystem module would be comprised of apertures, feeding and impedance matching networks.  The more sophisticated antenna subsystem could even have dynamic impedance and aperture matching network which is are tailored for the used channel on the fly.

Advanced 5G or even 6G wireless systems will support holographic 3D connectivity for virtual reality, which requires 10’s of Gbps connection.  The access points will be local and available at designated location where virtual reality services are supported.

This technology will be relying on both beamforming and MIMO.

Augment ORTENGA for WiGig antenna subsystem design and development.

 

Antenna Array Far Field Radiation Patterns

Antenna arrays are used to achieve higher directivity relative to the array element.

The radiation pattern of an array can be computed as

Far Field Radiation Pattern = |EF * PF * AF|2

where, EF, PF, and AF are Element Factor, Pattern Factor, and Array Factor.

Element Factor is infinitesimal factor of single element antenna

Pattern Factor is radiation pattern of single antenna due to its current distribution over the antenna

Array Factor is radiation pattern of array due to isotropic element

Each of the above factors can be computed standalone and their products is Far Field Radiation Pattern of the array.

For instance, Marconi-Franklin Linear array antennas are stacked 3 dipole antenna.

The element factor is Hertzian dipole pattern.

The Pattern factor is the radiation pattern of single dipole due to sinusoidal current excitation or distribution.  And the Array factor is the pattern due to isotropic elements array.

ORTENGA helps businesses to identify required technical features to realize their business goals.

 

Antenna Array with Mutual Couplings

When calculating antenna array pattern for complete accuracy, the pattern of an array antenna must include the variations in the excitation currents as well as the pattern of each element acting under the influence of all coupling effects.

This is a difficult task if not impossible; however there are 2 techniques for addressing this problem, namely; isolated element and active element pattern approach.

In the isolated element pattern approach, the coupling effect is accounted for in the current excitation and is appropriate for very large arrays.

In the active element pattern approach, all coupling effects are accounted for through the active element.

ORTENGA helps businesses to identify required technical features to realize their business goals.

 

Antenna vs. Frequency Selective Filter

From the electrical engineering perspective, a filter is a device that passes signals of interest in the desired frequency band while discriminating other/undesired frequencies.

An antenna is typically considered a transducer device, which converts guided electromagnetic waves to spherical waves.

Both filters and antennas are typically passive devices and reciprocal (i.e. input and output can be swapped).  What is less known about antenna, yet can be mathematically shown is that it behaves as a “spatial filter”.

From the Fourier Transform theory, we know that a narrow pulse, in time domain, has a wide frequency/spectral content (i.e. time and frequency are reciprocal to each other).   To pass such a narrow pulse signal, a wide band filter is required.  Similarly, a narrow far-field antenna radiation pattern requires to pass wide “spatial frequencies”.  In other words, the antenna has to be electrically large (i.e. relative to wavelength). That is why, in the radio astronomy community, an antenna is viewed as “spatial filter”.

ORTENGA helps businesses to identify required technical features to realize their business goals.

 

Antenna Surrounding

Antenna performance not only depends on its design topology but also on the surroundings which impacts antenna impedance in real world application.

In other words, if one were to design an antenna and meets all its required performance in standalone condition, then when it is embedded with other radio components, the antenna behavior would change, either over frequency or for worst.

In fact, mobile handset antennas are tuned with human phantom after fabrication, to adjust tuning elements in such a way that meets requirements in presence of the human body.

More advanced mobile handsets have capability of adjusting the tuning elements on the fly to account for various surroundings and still meets acceptable antenna performance.

Very advanced mobile handsets have capability of adjusting impedance and aperture tuning elements on the fly.

ORTENGA helps businesses to identify required technical features to realize their business goals.

 

Antenna Array Factor over Ground Plane

5G NR, gNB, LEO SATCOM,  radar, and WiGig rely on beamforming, therefore Active Electronically Scanned Antenna Array, AESA.  Typically AESA has ground plane, consequently image theory must be utilized to arrive at proper radiation pattern of AESA for simulation and therefore in actual applications.  This particularly becomes important and critical for implementing Beamforming, Beam steering, and SLL management algorithms.

The appropriate simulations enable the architect, system design, and managements to validate assumptions made for feasibility of design.  ORTENGA provides simulation tools to validate your design and goes beyond what appropriate Phase Array Tool Box or SystemVue provide, independently.

Augment ORTENGA into your architect and system design teams to validate design before its implementations.

 

Interference Cancellation

Radio interference cancellation is a technique in which the interfering radio signal is suppressed by placing a null in radiation pattern of antenna or antenna array systems.

Far Field or Fraunhofer radiation pattern of an antenna is function of current or field distribution over the antenna aperture.

Antenna proximity can be divided to 3 regions; Reactive near field, Radiating /Fresnel near field, and Far Field/Fraunhofer.

Radio communication energy is targeted for Far Field of an Antenna.

The idea of radio interference cancellation via radiation pattern is similar to suppressing an unwanted signal via filter.

In fact, antenna is a “spatial filter”, see Similarities of Filter vs. Antenna, posted on August 5th.  This technique assumes that the direction of interfering signal is prior knowledge or dynamically can be detected.

By forming antenna arrays, the radiation pattern of over antenna array can be adjusted dynamically via phase relationship between each antenna feeding.

Alternatively, if the radio interfering signal is placed at side lobe of the radiation pattern, the unwanted signal strength can be adjusted via current or field distribution of antenna array.

ORTENGA helps businesses to identify required technical features to realize their business goals.

 

Antenna Design by AI

Frequency selective filters can be designed by CAD tools such as Genesys.

Antenna is spatial selective filter and similarly can be designed by CAD.

In facts, antenna array governing equations are similar to frequency selective filter and can be similarly modeled.

Design optimization tools will be key to useful simulator for the end users.

The remaining challenge is how to form factor the antenna and conform to required space.

ORTENGA helps businesses to identify required technical features to realize their business goals.

 

Antenna Tuners 

Historically antenna tuners meant any passive interface impedance matching device between the antenna and the RF front end.

This terminology has carried over to UE and/or mobile devices.

In addition, as the need for multiple bands antenna increased, the need for antennas that can operate at multiple bands became prime interest of ODMs.

Nowadays, antenna tuning could either imply antenna impedance tuning or antenna aperture tuning.

The aperture tuning mechanism is part of antenna structure and changes antenna resonance frequency, hence operating at multiple bands.

ORTENGA helps businesses to identify required technical features to realize their business goals.

 

 

Sinuous Antenna

Log periodic antennas provide multi octave fractional bandwidth.

Sinuous antenna structure scales to multiple wavelengths gradually.

Therefore, it resonates at all of those wavelengths, consequently it has ideal antenna reception properties for UWB applications.

Sinuous antennas can be conformed to the desired space and be low profile.

Sinuous antenna radiation pattern is omni directional, hence low gain.

Consequently, they could be used in antenna array to achieve higher desired gain with proper array synthesis based on the application’s requirements.

ORTENGA helps businesses to identify required technical features to realize their business goals.

 

Vivaldi Antenna

Log periodic antennas provide multi octave fractional bandwidth.

Tapered Vivaldi antenna structure scales to multiple wavelengths gradually.

Therefore, it resonates at all of those wavelengths, consequently it has ideal antenna reception properties for UWB applications.

3D and 2D Vivaldi antennas are used for various applications both in receiver and transmitter chains.

Vivaldi antennas have some gain that can be tailored for specific applications as single element.

Vivaldi antennas can also be used in antenna array to achieve higher gain, consequently lower beamwidth for beamforming applications.

ORTENGA helps businesses to identify required technical features to realize their business goals.