Industry-University Cooperation Foundation Hanyang University

Electronics and Telecommunications Research Institute

Oe Solutions Co., Ltd.

Tae-Yeoul Yun

Ji-Young Lee

Jun-Young Park

Moon Soo Park

Chang Sun Kim

Seong Hoon Choi

Hee-woo An

Yea Chul Roh

Yun-mo Kang

Yong Deok Kim

Tu Tuan Le

A wearable antenna comprises: an upper substrate made of a solid material; an inner open ring radiator formed on an upper surface of the upper substrate and having a first slit formed therein; an outer open ring radiator formed in a ring shape having the same center as the inner open ring radiator and having a larger radius on the upper surface, and having a second slit formed therein to open a partial area; a feeding portion formed on a lower surface of the upper substrate and transmitting a feed signal applied from an input port to each of the two open ring radiators through two vias penetrating the upper substrate; a lower substrate spaced apart from the lower surface of the upper substrate by a predetermined distance and made of a flexible material; and a ground plane formed on a lower surface of the lower substrate.

Dual-open-ring wearable antenna

Disclosed is an optical communication receiver capable of compensating a DC offset while preventing an input load effect. The optical communication receiver includes an optical signal detector; an amplifier inputted with a photocurrent outputted from the optical signal detector; and a DC offset compensation unit provided therein with a third transistor and a fifth transistor which are connected in series to each other to prevent an input load effect, wherein the DC offset compensation unit compensates a DC offset by outputting at least a portion of DC current inputted to the amplifier to ground through the third transistor and the fifth transistor when the photocurrent is an over current more than a predetermined set value.

Optical receiver for compensating DC offset

Provided is a frequency conversion mixer. The frequency conversion mixer includes a transconductance stage, a switching stage, a load stage, a current bleeding circuit, and a bias stage. The transconductance stage receives an RF signal, and outputs a current corresponding to a voltage of the RF signal. The switching stage switches the current which is outputted from the transconductance stage in response to a local oscillation signal, for frequency conversion the RF signal into an intermediate frequency (IF) signal. The load stage is connected between the switching stage and a supply voltage terminal. The current bleeding circuit is connected parallel with the switching stage, especially, embodying inverter structure with transconductance stage to get not only current bleeding effect but also current reuse effect, and one resonant inductor for reducing noise which is generated in parasitic capacitance at node between transconductance stage and switching stage. The bias stage is connected between the transconductance stage and a ground terminal, and has the switched biasing technique for allowing not only the stable bias current but also lowering the flicker noise.

Frequency conversion mixer

Growing community of inventors

Seoul, South Korea

Tae-Yeoul Yun