1 / 14

A Multi Unsymmetrical Beam Tapered Slot Ya-gi Antenna with λ/4 for PMMW Imaging

A Multi Unsymmetrical Beam Tapered Slot Ya-gi Antenna with λ/4 for PMMW Imaging. Presenter: Ya Chung Yu. Out Line. Introduction Specification Antenna design Multi unsymmetrical beam antenna design Summary. Introduction. Passive millimeter wave imaging (76~110GHz) Effective detection

alyssa
Download Presentation

A Multi Unsymmetrical Beam Tapered Slot Ya-gi Antenna with λ/4 for PMMW Imaging

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. A Multi Unsymmetrical Beam Tapered Slot Ya-gi Antenna with λ/4 for PMMW Imaging Presenter: Ya Chung Yu

  2. Out Line • Introduction • Specification • Antenna design • Multi unsymmetrical beam antenna design • Summary Company Logo

  3. Introduction • Passive millimeter wave imaging (76~110GHz) Effective detection • Reveals any material: metal, liquids and gels, contraband, sheet and bulk explosives • Several millimeter resolution Efficient, easy to carry and image • Small size and portable • Single scan without changing position (multiple views with one scan) • Primary and/or secondary screening Respects Privacy • Imaging system shows 3-D black and white silhouette, which is not stored • Options for privacy blurring, remote viewing and gender specific viewing • Automatic detection option to support or replace analyst review of image Harmless • NOT X-ray technology • Only receive heat radiation Company Logo

  4. Key components of PMMW imaging system • High efficiency lens antenna • low noise amplifier (LNA) • Low bias power detector • Critical performance • Temperature resolution • Where k: Boltzmann constant T: Absolute temperature T0: Ambient temperature F: Noise Figure B: RF bandwidth : Integration time • Spatial resolution depends on Lens size and feed antenna design Company Logo

  5. 70度 15cm 100cm Specification Detection distance: 1~3 m Spatial resolution: 2 cm @ 1 m detection distance Temperature resolution: 0.5 K Field of View: 22 cm × 22 cm (pixel: 11 × 11) Company Logo

  6. Antenna design • Antipodal tapered slot antenna - PCB layout (duroid 5880), low cost, low losstangent - endfire radiation pattern, a pixel corresponds to an antenna • Bandwidth 20GHz (78~98GHz) - satisfy the requirement of the temperature resolution • 3 dB beamwidth 70 degree - satisfy the lens specifications (focal length of 15cm & lens diameter of 20cm) Challenge problem: Company Logo

  7. Symmetrical pattern 3dB beamwidth 70° Multi unsymmetrical beam antenna design • Original symmetrical tapered slot ya-gi antenna form • antipodal tapered slot • ya-gi directors • λ/4 fan rejections • at focal point of lens Return Loss (dB) Co-pole pattern (dB) 90° Company Logo

  8. Unsymmetrical beam form (perturbation method) • λ/4 fan rejections (broadband structure) • control traveling current phase (perturb current directions) • reduced coupling interference • at off axis focal plane Company Logo

  9. Left unsymmetrical tapered slot ya-gi antenna • current phase of right arm is slower than left one • Left part of pattern is smoother than right part • Main beam shift 10° to right • 3dB beamwidth is also 70° Company Logo

  10. Right unsymmetrical tapered slot ya-gi antenna • current phase of left arm is slower than right one • right part of pattern is smoother than left part • Main beam shift 10° to left • 3dB beamwidth is also 70° Company Logo

  11. Comparison Sym Left Right Company Logo

  12. Lens W-band Antenna W-band chip (LNA & PD) DC bias DC output • Feed antenna array λ/4 fan rejections Company Logo

  13. Summary • Multi beam unsymmetrical tapered slot ya-gi antenna is useful for near field focusing lens, especially in the condition of the wider imaging range • It is easy to change radiation pattern with quarter-wavelength fan rejection structure without rotating physical angle • Reduce the area of layout and loss Company Logo

  14. Thanks for Listening Company Logo

More Related