Multi-Port Driven Radiators

Abstract

Integrated multi-port driven (MPD) radiator design is presented as an approach that takes advantage of the increased design space offered by using a hybrid design of an antenna with multiple ports and its driver circuitry integrated together on a single substrate. This reduces costly losses by eliminating independent elements for power combination, output impedance matching networks, and power transfer by engineering current patterns on a chip based on the desired far field pattern. The electromagnetic radiation produced by a circularly polarized MPD antenna is calculated analytically to provide design intuition, with supporting electromagnetic simulations. A single element 160 GHz MPD antenna and the supporting driver circuitry is designed and fabricated in a 0.13 SiGe BiCMOS process. A tuned 8 phase ring oscillator generates the signal with each phase feeding class A power amplifiers that drive the antenna. The radiator achieves 4.6 dBm single element effective isotropically radiated power (EIRP) and total radiated power of 2.0 dBm at 161 GHz while consuming 117.5 mA DC current from a 3.3 V source. Measurements of three frequency bands at 145, 154 and 161 GHz show greater than 0 dBm EIRP for each band, demonstrating the wide band nature of the antenna.Index Terms-Antenna theory and design, EM simulation, integrated microwave circuits, integrated radiators, millimeterwave silicon RFICs, on-chip antennas, quasi-optical power combining, SiGe BiCMOS.

Slot-ring multiport driven antenna with improved airside radiation for terahertz communications

“…Figure 1 shows the simulated directivity of the slotring with an electrically thick substrate. The pattern is on the backside of the substrate as is was the case in [7] but with significant lateral radiation. The electrically thick substrate supports more substrate modes which exit the substrate at the edges and cause lateral radiation which is also emphasized at the corners of the substrate.…”

“…We achieve this by adjusting the geometry of the outer ground plane to a circle and placing a ground plane on the backside of the substrate. The ring MPD presented in [7] uses a ground plane on the backside of the substrate but places a quarter wavelength substrate thickness requirement to guarantee coherent integration of the waves reflected from the ground for effective radiation. In this study a 2.25λ (9 quarter wavelengths) thick substrate is used.…”

“…MULTIPORT DRIVEN SLOT-RING ANTENNA Multiport driven (MPD) radiators offer the possibility to obtain high radiation efficiency even with low input impedance antennas and power combining by the antenna [7]. An eight source multiport driven radiator designed for 155 GHz operation implemented using a conductor ring with a wheel and spoke geometry on a quarter-wavelength thick silicon substrate with a reported gain of 4.4 dBi, 9.71 dBi maximum directivity and 30 % efficiency was described in [7]. The key design parameter of an MPD ring antenna is g = 2πr/λ, the circumference to wavelength ratio of the ring, where r is the radius of the loop.…”

“…The design criteria is to create a loop with 1 < g < π/2 in order to get the currents on the opposite halves of the loop and the center spokes to add up coherently and radiate effectively. The design in [7] features an multilayered structure with the spokes on a lower level and ring on a plane above the spokes, and two ground planes. A design challenge with the ring MPD antenna is to route the tracks to the driven points along the ring.…”

An integrated traveling-wave slot radiator

“…Because the integrated circuit (IC) itself is on the same order of magnitude as the wavelength at these frequencies, integrating the drivers and antennas on the same substrate to create an integrated radiator has become feasible. Recent work has shown that reasonable efficiencies and power levels of integrated radiators can be achieved without the need for external dielectrics or lenses [1]- [3], decreasing the cost and volume requirements of such devices significantly.…”