100MHz, 6th Order, Leap-Frog gm-C High Q Bandpass Filter and On-Chip Tuning Scheme

Abstract

-A 100MHz centre frequency, 10MHz bandwidth 6th grounded capacitors. The circuit can be divided into order Butterworth bandpass filter using a leap-frog gm-C capacitively-loaded gyrator "resonators"(gm3, 4, 7, 8, 11, structure is described. Fully differential Nauta OTAs are used 12), and inter-resonator "coupling" OTAs (gm5, gm6, gm9, in the design, which include compensation of parasitic output gmIO). The remaining OTAs form the terminating resistance and feed-forward effects to obtain high Q. A mixedresistances (gm2, gml4), and gain-setting input and output signal, on-chip tuning system based on Dishal's method is ' f described. The filter and tuning system have been simulated buffers forthe filter (gml, gml3).

A 100 MHz G<inf>m</inf>-C bandpass filter chip design for wireless application

“…The remaining OTAs are the terminating resistances (g m2 , g m14 ), and gain-setting input and output buffers for the filter (g m1 , g m13 ) [7].…”

Explicit design formulas for current‐mode leap‐frog OTA‐C filters and 300 MHz CMOS seventh‐order linear phase filter

“…Note that the denominators of the corresponding transfer functions have already been given in Section 2 and the design formulas for the pole parameters j of the respective orders have also been given in Equation (4). In addition, if the maximum order in the numerator is required to be n −1, then we can remove the g a(n+1) OTA and simply output the current I on directly.…”

“…Continuous-time integrated filter design has developed very rapidly over the last twenty years [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20]. Although active-RC filters continue to be useful in areas such as transceiver baseband [19], OTA-C filters have become dominant [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18] in many applications, including computer hard disk drive (HDD) read/write channels [3,[14][15][16]. Analogue signal processing in the current domain can offer certain advantages for many applications and current-mode continuous-time filters have (1) where I input is the overall input current and I output is the overall output current of the filter, respectively, I o j is the output current of the jth integrator and s is the complex frequency.…”

“…This paper aims to achieve the above.The leap-frog (LF) structure is no doubt one of the most popular choices in continuous-time filter design [1]. It has some obvious advantages compared with other structures such as the cascade and inverse-follow-the-leader-feedback (IFLF) [2], especially in terms of sensitivity, and is widely used for high-performance filter applications with stringent requirements [3,4]. Traditional filter designs based on the LF structure are too complex, as they are based on the simulation of passive RLC ladder prototypes [1,[4][5][6][7][8] or using a multiple loop feedback (MLF) theory [1-3].…”

A UHF CMOS Gm-C bandpass filter and automatic tuning design

“…A high-quality-factor integrated continuous bandpass filter is great needed. In the recent years, the improvement of the UHF filter design is witnessed and people apply MOSEFT-C filter, RC active filter and Gm-C filter in the practical industry [1] [2][3] [4]. The Gm-C architecture has attracted much interest for its simple and symmetrical structure and good response tribute, especially which the Gm-C filter is composed of active transconductor components and ω c , Q-factor can be tuned by the bias voltage.…”