Previous Design Work Zeynep Dilli

Some Design Projects Optical System Design: A Borescope (ENEE 408E) Electronics Circuit Design: AM Radio System (ENEE 719) Chip Design: Parasitic Load Measurements (research work) Others: An Optical Keyboard, A Pulse Width Modulator, An External Cavity Laser (undergraduate and previous research work)

Borescope Design Borescope: An optical device used to examine narrow and inaccessible spaces, e.g. inside a gun barrel or engine cylinder Specifications: Diameter <25 mm; cost <$1000; design for a CCD camera as an eyepiece; image acceptance angle ±25º; periodic relay system to ensure extensibility. Design decisions: Lenses w/ diameter <15 mm; commercial lenses from Melles-Griot; aim for a focused image to be aligned with focal lens of a CCD camera.

Borescope Sections Objective: Achromatic doublets to create a well-focused image of an object close to the lens with a wide angle. Field Lens: Refocus the rays to make propagation direction more axial. Relay System: Carry the image long distances without extra distortion. Objective Field Lens This is 25 cm long. Adding relay units it can be extended to 34 cm, 43 cm…This is 25 cm long. Adding relay units it can be extended to 34 cm, 43 cm…

AM Radio Radio receiver/demodulator in the AM range: –  between approximately 500 kHz and 1500kHz –  c between approximately 500 kHz and 1500kHz –  IF at AM standard, 455 kHz –  LO then has to vary between 955 kHz and 1955 kHz

AM Radio Frequency Domain Operation-1 AM-Modulated signalAM-Modulated signal After the LO Mixer---the LO operatingAfter the LO Mixer---the LO operating frequency is what we tune;  LO-  c=  IF where  c is the carrier frequency. After the IF filterAfter the IF filter

AM Radio Frequency Domain Operation-2 After IF amplificationAfter IF amplification After IF MixerAfter IF Mixer After the LPF---Audio-frequency signal.After the LPF---Audio-frequency signal.

AM Radio Time Domain Operation

Chip Designs Objective: Measure loading effects of bonding padsObjective: Measure loading effects of bonding pads

Effect of Pads—Test Setup Left: “External” ring oscillator, 11 stages (two stages are shown). Connection between stages require going out to the board through bonding pads, wires and pins. Both are comprised of minimum-size transistors, simulated speed for 31 stages: 132 MHz. Below: Internal ring oscillator, 31 stages, output to divide-by-64 counter. Direct connection between stages.

Effect of Pads—Results Summary Internal Osc. External Osc. One-stage delay 112 MHz (31-stage) (equivalent to 1.16 GHz for 3 stages) 398 KHz (11-stage) (equivalent to 1.46 MHz for 3 stages) ~330 ps for internal, ~330 ns for external devices 0.6  m chip, measurements taken by Tektronix oscilloscope with 1 pF-capacitance active probe on the breadboard Speed ratio: Load ratio: ~1000

3-D Integration: “Symmetric” Chip Chip with structures that can be connected in 3D and planar counterparts for comparison

3-D Connections: “Symmetric” Chip Same 31-stage planar ring oscillator with counter output Also 31-stage 3-D ring oscillator with counter output (On the figure, groups of ). To counter input Simulation results: Planar: 142 MHz 3-D, six “layer”s : 122 MHz “symmetry” axis The proper pairs of pads have to be connected to each other through vertical through-chip vias post-fabrication for the circle to close.