A dispersion discriminator and method for determining the amount of dispersion in an optical signal. At least one of the cell sites has multiple receive antennas. The sleeve is removable and, optionally, reusable. For the cells of the same column, the two power-switches respectively perform independent supply voltage controls for the two inverters in each cell according to data-in voltages of the bit-lines during Write operation. In one aspect, the reed valve is configured to create backpressure at the membrane that affects the rate of flow at the flexible membrane.