What is Antenna?
Antenna is an electrical device (transducer) used to transform electrical power to RF waves, and vice versa.
For designing an antenna, as an antenna design engineer, you need to know, what is the desired frequency, gain, bandwidth, impedance, and polarization? If you never heard of these parameters, these are antenna fundamental parameters which characterize an antenna.
Antenna Fundamental Parameters:
- Radiation Pattern
- Radiation Efficiency
- Return Loss
Today’s Small Antenna Requirements :
- High Efficiency
- Working in complex environment
- Cost effective
Ansys Electromagnetics products predict antenna design performance and EMI-EMC failures for wide variety of applications:
- Mobile phones, smart wearables, tablets, PCs, hearing aids, MP3 players, laptops, TVs, gaming consoles
- Automotive telematics, infotainment, navigation and driver assistance
- Telecommunications networks
- Aerospace, military and satellite communications
The implantable antennas are used for communication purposes in implant medical devices such as cardiac pacemakers, neuro-stimulators, drug monitoring, healthcare sensors and monitoring devices, and implant control devices. Designing antennas for implanted devices is an extremely challenging task. The antennas require to be small, low profile, and multiband. Additionally, antennas need to operate in complex environments. Factors such as small size, low power requirement, and impedance matching play significant role in the design procedure. The MICS band of 402-405 MHz is a common wireless telemetry for implantable medical devices. With HFSS, a small implantable Planar Inverted F Antenna (PIFA) is designed for MICS band and optimized in presence of human body model.
The wide and fast growing application of wireless devices yields to a lot of concerns about their safety standards. The Specific Absorbtion Rate (SAR), which measures the electromagnetic power density absorbed by the human body tissue, is considered as an index by FCC to regulate the amount of exposure of the human body to electromagnetic radiation.
Ansys HFSS is a valuable tool in antenna design and platform integration that allow engineers to look beyond the antenna design and begin considering how it interacts with the system or platform into which it is integrated. HFSS Technology offers HFSS Finite Element Method (FEM), HFSS Integral-Equation (IE), HFSS Physical Optics (PO), and HFSS Transient. These antenna simulation methods and tools can be used depending upon the kind of problem you want to solve.
Antenna integration is a complex multi-scale and multi-domain problem. The major challenges in antenna integration modeling are accuracy, electrical size and scale, geometric complexity, platform materials, placement and co-site interference, and solution time. The antenna performance/characteristic can be affected after integrating on the platform (Far-Field pattern degraded, input impedance detuned…). Successful Integration of antenna systems on platforms requires that the design engineers overcome these challenge. Here are some tips and tricks to overcome the challenges:
- De-feature models obtained from mechanical or electrical CAD tools when possible. (These models typically include geometry details insignificant for electromagnetic analysis)
- Removing unnecessary model details reduces mesh density and runtime. (Use good engineering judgment to make certain that removed features are electrically insignificant)
- Using Ansys Electronics High Performance Computing (HPC) to reduce run time.
- Using HFSS Hybrid Solution (Integral Equation, Physical Optics) or HFSS integration with SAVANT for large electrical size and scale.