公开(公告)号：US06018275A

公开(公告)日：2000-01-25

申请号：US993268

申请日：1997-12-18

Applicant: Alan Christopher Perrett ,  Kenneth Peter Mason

Inventor： Alan Christopher Perrett ,  Kenneth Peter Mason

IPC: H03C3/09 ,  H03C3/00 ,  H04L27/04 ,  H04L27/12 ,  H04L27/20

CPC classification number: H03C3/0983 ,  H03C3/095 ,  H03C3/0958 ,  H03C3/0966 ,  H03C3/0975

Abstract: A transmitter and a phase locked loop (30) for a transmitter are disclosed. The phase locked loop (30) upconverts the frequency of a baseband signal to a frequency for radio transmission. As well as the usual components, the phase locked loop (30) comprises a modulator (39) for modulating a baseband signal (f.sub.bb) onto a carrier (f.sub.ref /R) and forwarding the resultant modulated signal (f.sub.c) to one of the inputs of the phase detector (33). It also comprises a low pass filter (38) in its forward path between the phase detector (33) and the voltage controlled oscillator (34) for passing signals having baseband signal frequencies. A mixer (35) and main frequency divider (36) are provided in the feedback path to downconvert the transmit signal (f.sub.tx). This low division eliminates large amounts of multiplicative noise within the loop bandwidth, and therefore enables a large loop bandwidth to be used. Consequently, the settling time of the phase locked loop is improved.

Abstract translation: 公开了用于发射机的发射机和锁相环（30）。 锁相环（30）将基带信号的频率上变频到无线电传输的频率。 除了通常的组件之外，锁相环（30）包括用于将基带信号（fbb）调制到载波（fref / R）上的调制器（39），并将所得到的调制信号（fc）转发到输入 的相位检测器（33）。 它还包括在相位检测器（33）和压控振荡器（34）之间的正向通路中的低通滤波器（38），用于通过具有基带信号频率的信号。 在反馈路径中设置混频器（35）和主分频器（36），以对发射信号（ftx）进行下变频。 该低分频消除环路带宽内的大量乘法噪声，因此能够使用较大的环路带宽。 因此，提高了锁相环的稳定时间。