Research 

Research Impact: 

Many medical devices, mobile phones, Wi-Fi modules, aircrafts, underwater vehicles etc. require antennas with low-profile and compact size. Miniaturization of antenna is especially crucial for medical applications such as near-field microwave imaging, implantable device design, wireless power transfer to implants etc. However, with the reduction of the antenna size, the bandwidth and gain get reduced too. The trouble for the antenna design engineers exacerbates due to the fact that, compact antennas tend to operate at high frequencies. Hence miniaturization of antennas for applications such as- microwave imaging, which require low frequency EM waves for longer penetration depth into the subject, involves several challenges and trade-offs.

Dr. Parveen's research focus is on exploring different miniaturization techniques such as- use of high permittivity substrates, use of superstrates, use of corrugated surfaces, use of defective ground planes etc. to achieve desired operating frequency and radiation characteristics even after substantial reduction of the antenna size. 

Research Impact: 

Applications that exploit the radiating near-field of an antenna, such as- near field microwave imaging etc., often require directional radiation pattern in the near-field to reduce the reception of unwanted back-scatter from the environment surrounding the subject. However, due to the structural constraints on the antenna for that application, several higher order modes get activated and propagate through the antenna. Each of these higher order modes have their separate resonant frequencies, and the antenna surface current at a particular frequency can be considered to be the sum of all these modal currents. Different characteristic currents have different radiation efficiencies at a particular frequency. These higher order mode currents may cause high gain spurious radiation toward the backward direction and hence distort the directional radiation pattern of the antenna.

Dr. Parveen's research plan is to analyze the surface current and radiation pattern of the antenna associated with each higher order mode, and to figure out which part of the antenna is contributing for the resonance of each higher order mode at their respective resonant frequencies. Based on this analysis the antenna structure, excitation/ feed point etc. can be modified to suppress any modal current that is creating radiation toward unwanted directions. 

Research Impact: 

Many medical emergencies require imaging of part of the human body such as- brain, breast, bone, lungs etc. Furthermore, some medical cases may need continuous monitoring of the subjects’ internal organs for improvised medication or treatment. Traditional imaging modalities such as- MRI, CT scan etc. can facilitate precise detection of lesions or monitoring internal organs of the subject. However, these modalities are expensive, require bulky setup, and can cause long-term health hazard, restricting the frequent use of them anywhere by anyone. Microwave imaging can be an effective alternative to these modalities for providing solutions to imaging requirements. Though, the microwave imaging cannot provide as precise image as that of MRI or CT scan, it can give an approximate estimate of the presence and location of probable anomaly inside the suspected region. Furthermore, it can be considered for frequent use and can be availed by poor people anytime at any place, as it uses non-ionizing radiation for imaging using an inexpensive and simple setup.

Dr. Parveen's research focuses on microwave imaging of the human brain, for the detection of blood clots inside the brain due to stroke or traumatic brain injuries. This work involves the design of both the antenna and imaging setup, and investigation of different imaging algorithm for obtaining improved image of the brain.